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: aiam3396OpenMr. O. Vandewege, President, PolyDyne Engineering, Box 3517, Scottsdale, AZ 85257; Mr. O. Vandewege President PolyDyne Engineering Box 3517 Scottsdale AZ 85257; Dear Mr. Vandwege: This responds to your letter of March 6, 1981, to Joseph Zemaitis Motor Vehicle Program Director, Region IX, regarding Safety Standard No. 125, *Warning Devices*. You wish to obtain approval of your warning device (the 'short stop') for use on trucks and trailers. Your device is a collapsible reflective triangle that is designed to be permanently mounted on the side or rear of a vehicle.; The National Traffic and Motor Vehicle Safety Act of 1966, as amende (the Act), authorizes the National Highway Traffic Safety Administration to issue Federal motor vehicle safety standards which are applicable to motor vehicles or motor vehicle equipment. Safety Standard No. 125, *Warning Devices*, establishes requirements for devices that are designed to be carried in motor vehicles and used to warn approaching traffic of the presence of a stopped vehicle. The rule does not apply to warning devices that are designed to be permanently affixed to the vehicle, and thus does not apply to your device. Hence, it is not necessary for you to obtain the 'approval' of this agency before you may manufacture or sell a 'short stop' or before an owner may use such a warning device on his vehicle.; However, the Federal Highway Administration (FHWA) has promulgated regulation (49 CFR S393.95) regarding the use of emergency equipment on heavy duty trucks and buses that are used in interstate commerce. This standard may prohibit the use of warning devices such as the 'short stop' on certain types of vehicles. Since the FHWA can best address this issue, we have forwarded your letter to that agency's Chief Counsel for response. The address of that office is Room 4213, 400 Seventh Street, S.W., Washington, D.C. 20590.; We hope you find this information helfpul. Please contact this offic if you have any questions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4453OpenMr. Lloyd J. Osborn Chief, Customs and Quarantine Division Department of Commerce Government of Guam 590 South Marine Drive Suite 601, 6th Floor GITC Building Tamuning, Guam 96911; Mr. Lloyd J. Osborn Chief Customs and Quarantine Division Department of Commerce Government of Guam 590 South Marine Drive Suite 601 6th Floor GITC Building Tamuning Guam 96911; "Dear Mr. Osborn: This is in reply to your letter of December 11, 1987 to the Office of Vehicle Safety Standards of this agency in which you request a 'list of vehicles which have been determined by NHTSA to be excluded as motor vehicles.' The agency does not maintain a list of this nature. The National Traffic and Motor Vehicle Safety Act defines a 'motor vehicle' as a vehicle, with or without motive power, manufactured primarily for use on the public streets, roads, and highways. This category includes vehicles capable of off-road use but which are nevertheless generally licensed for use on the public roads. Over the years, NHTSA has provided interpretations that the following types of vehicles are not 'motor vehicles': single seat racing cars, stock cars modified to the point that they are no longer licensable for use on the public roads, all-terrain vehicles, racing motorcycles and off-road motorcycles that are trailered over the public roads, golf carts, in-plant vehicles lacking doors and lighting devices, airport crash and rescue vehicles, and shuttle buses, snowmobiles, mobile homes, farm tractors, farm trailers whose use of the public roads is limited to crossing from one field to another, and trailers like mobile compressors which spend lengthy periods of time at an off road worksite and only infrequently travel by road to a new worksite. In addition, the agency does not consider construction cranes to be 'motor vehicles'. Finally, vehicles manufactured pursuant to military contracts, while 'motor vehicles', are nevertheless exempted from compliance with the Federal motor vehicle safety standards. If you have any further questions we shall be happy to answer them, as well as furnish whatever other assistance you may require in formulating your Customs procedures. Sincerely, Erika Z. Jones Chief Counsel"; |
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ID: aiam1651OpenMr. M. C. Bartlett, Manager, Product Liability, B. F. Goodrich Tire Company, 500 South Main Street, Akron, OH 44318; Mr. M. C. Bartlett Manager Product Liability B. F. Goodrich Tire Company 500 South Main Street Akron OH 44318; Dear Mr. Bartlett: We have reviewed your draft defect notification letter forwarded to u on October 22, 1974, regarding the Space Saver Spare Tire. We find that this letter fails to conform to 49 CFR Part 577, 'Defect Notification' in that it fails to provide a clear description of the defect (S 577.4(c)). In our letter to Goodrich of September 24, 1974, we advised you, based on your earlier draft notification letter, that we did not agree with your characterization of the malfunction as relating to only those tire explosions which you believe will cause injury. We objected to your position that broken beads and excessive air pressure must appear in combination for an explosion to occur. We also informed you that you must make it clear that bolting the tire to the vehicle has no effect whatever on whether the tire will explode, but that bolting will serve only to reduce the chance of injury if an explosion occurs.; Your letter of October 22 is not sufficiently responsive to ou September 24, 1974, letter. The third sentence of your second paragraph reads, 'When the wheel is not bolted to the axle during inflation, the combination of improper mounting and/or excessive air pressure can cause the tire to explode-- serious personal injury or death can result.' This sentence again refers to the necessity of the particular factors appearing in combination for an explosion to occur (the 'and/or' is ambiguous in this context) and more importantly, implies that bolting the tire to the vehicle has some relationship to the possibility of an explosion. We have decided to suggest language for you to use in your notification in order to avoid further problems. We believe your second paragraph, beginning with its second sentence, should be changed to read as follows:; >>>'The defect is caused by improper mounting or subsequent remountin of the tire on the rim causing the tire bead to seat improperly on the rim, or by excessive air pressure from a high pressure air supply being forced into the tire. Improper mounting or excessive air pressure can cause the tire to explode during inflation. If the precautions specified on page 2 of this letter are not followed, serious personal injury or death can result.'<<<; Your fourth paragraph similarly enforces the implication that boltin the tire to the vehicle will affect the possibility of an explosion. We do not consider this paragraph to be necessary as it merely repeats your second paragraph (if rewritten as indicated above). However, if you insist that it be included, we believe it should be written as follows:; >>>'An explosion of the Space Saver Spare tire assembly has occurre when either of the two following conditions were present:; 1. Improper mounting or remounting of the tire on the rim created broken tire bead, or; 2. Excessive air pressure from a high pressure air supply was force into the tire.; However, if the tire is bolted to the axle during inflation, and th other precautionary procedures described below are followed, the danger of serious injury or fatal accidents is greatly reduced.'<<<; We view the words 'virtually eliminated' which are in your draft a excessively optimistic under the circumstances. It is difficult for us to believe that an exploding tire has virtually no chance of causing injury to one who is inflating it and who must, under the circumstances, be situated very close to it.; We repeat that our review of your letter represents in no way a agreement with your analysis of the defect or its causes, and that we will continue to look into this matter as appropriate. Consumer notification of this serious safety hazard has been too long delayed. We trust that the statutory defect notification will issue forthwith.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam0943OpenMr. David J. Humphreys, RVI Washington Counsel, Recreational Vehicle Institute, Inc., Suite 406, 1140 Connecticut Avenue, Washington, D.C. 20006; Mr. David J. Humphreys RVI Washington Counsel Recreational Vehicle Institute Inc. Suite 406 1140 Connecticut Avenue Washington D.C. 20006; Dear Mr. Humphreys: This is in reply to your letter of December 12, 1972, concernin Standard No. 126. In essence you object to the requirements effective January 1, 1973, that the camper manufacturers furnish the camper purchaser a statement advising him to select a truck 'whose manufacturer recommends a cargo center of gravity that will contain the camper's center of gravity when it is installed.' You base your objection upon the feeling that use of such language may mislead dealers and purchasers since camper manufactures are not required to provide center of gravity information until September 1, 1973. You ask if it is permissible to add the qualifying phrase '(if the camper has a center of gravity indicated)' to the language quoted and required by Standard No. 126.; We anticipate that many camper manufacturers will be able to provid center of gravity information before September 1, 1973. Inclusion of the language you request would, in our judgement, discourage prospective purchasers of a truck-camper combination from searching for a proper match if the camper at hand which he is examining does not have a center of gravity indicated. The language in question is an advisory caution only, and in our judgement does not impose an unreasonable burden on any of the parties concerned. For these reasons, Your request is denied.; If the required language is included, however, a camper manufacturer i not prohibited from also including a notation that center of gravity information is required to be furnished only with campers manufactured on or after September 1, 1973.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4003OpenMr. Thomas J. Burke, Vice President - Domestic Sales, Hess & Eisenhardt Armoring Company, 8959 Blue Ash Road, Cincinnati, OH 45242; Mr. Thomas J. Burke Vice President - Domestic Sales Hess & Eisenhardt Armoring Company 8959 Blue Ash Road Cincinnati OH 45242; Dear Mr. Burke: Thank you for your letter of July 3, 1985, to Mr. Burdette and Mr Brownlee concerning a new automobile safety package your company is developing. Your letter was referred to my office for reply. You described your product as a number of modifications to a vehicle to improve its security. The modifications include changes to the windows, tires, doors, and fuel tank. I hope the following discussion explains how our regulations would affect your product.; The National Traffic and Motor Vehicle Safety Act authorizes th National Highway Traffic Safety Administration (NHTSA) to issue Federal Motor Vehicle Safety Standards for new motor vehicles and items of motor vehicle equipment. Under that authority, NHTSA has issued vehicle safety standards on a wide variety of subjects, including on tires, windows, doors and fuel tanks. I am enclosing an information sheet explaining how you can obtain copies of our standards. A manufacturer of new vehicles must certify that its vehicles conform to the requirements of all applicable safety standards. Under our certification regulation, Part 567, *Certification* (49 CFR Part 567), a person who modifies a vehicle prior to its first sale to the consumer is considered an 'alterer.' Part 567.7 requires vehicle alterers to certify that the vehicle, as altered, conforms to all of our safety standards. Thus, if your company is modifying vehicles with your security package prior to their first sale to the consumer, it must certify that the vehicles, as altered, conform with all applicable standards. Any person who fails to comply with our certification regulations is subject to civil penalties under the Vehicle Safety Act.; If your company is modifying used vehicles, then its actions would b affected by section 108(a)(2)(A) of the Vehicle Safety Act (15 U.S.C. S1397(a)(2)(A)), which was added to the Act in 1974 to address the problem of persons tampering with safety equipment installed on a motor vehicle. Section 108(a)(2)(A) provides, in part, that:; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or 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.....<<<; Thus, a manufacturer, distributor, dealer, or motor vehicle repai business making the modifications you describe must ensure that those modifications do not 'render inoperative' the compliance of the vehicle with any safety standard. The Vehicle Safety Act provides for civil penalties for persons that 'render inoperative' an element of a safety standard.; I hope this information is of assistance to you. If you have furthe questions, please let me know.; Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam1201OpenMr. Charles J. Calvin, Managing Director, Truck Trailer Manufacturers Association, 2430 Pennsylvania Avenue, N.W., Washington, DC 20037; Mr. Charles J. Calvin Managing Director Truck Trailer Manufacturers Association 2430 Pennsylvania Avenue N.W. Washington DC 20037; Dear Mr. Calvin: This is in reply to your letter of July 5, 1973, requesting a unifor location for trailer certifications labels required by both the Hazardous Materials regulations (49 CFR S 178.340-10) and NHTSA Certification regulations (49 CFR Part 567). You request that location be specified as the 'forward half of the left side of the trailer.'; NHTSA Certification regulations, as you note, presently provide tha the certification label for trailers must be placed on the 'forward half of the left side of the vehicle' (49 CFR S 567.4(d)). This requirement does not distinguish between the frame and the tank shell, and the reference to 'vehicle' in the language of the provision is considered inclusion of both. The Certification regulations therefore appear to permit the location of the label that you request.; I note, however, the drawings in your letter, those titled 'Acceptabl Locations of Certification Labels' and 'Suggested Locations for Certification Labels', picture as an appropriate label location the front of the vehicle.; This location is not permitted by the NHTSA Certification regulations which clearly call for the label to be affixed to the vehicle 'left side'. While it is not clear whether you intended to request that the label be permitted to be affixed to the vehicle front, we do not find sufficient justification in your letter to depart from the existing requirements in this regard.; Sincerely, James E. Wilson, Associate Administrator, Traffic Safet Programs; |
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ID: aiam1714OpenMr. David D. Anderson, Chairman, ASTM Subcommittee E17.24, Tire and Slider characteristics, General Motors Proving Ground, Milford, Michigan 48042; Mr. David D. Anderson Chairman ASTM Subcommittee E17.24 Tire and Slider characteristics General Motors Proving Ground Milford Michigan 48042; Dear Mr. Anderson: This is in reply to your letters of October 25, and November 5, 1974 requesting our opinion on whether a tire recently approved by ASTM for special purpose highway and airport runway skid resistance tests must conform to Motor Vehicle Safety Standard No. 109 (49 CFR S 571.109), and whether it may be used for skid resistance testing on highways and airport runways. You describe the tire as a G778-15 of bias-belted construction (2-ply polyester sidewall and 2 fiberglass belts), having a tread with no grooves or sipes. You indicate that due to the tread configuration the tire will not meet the high speed performance requirements (S4.2.2.6) of Standard No. 109.; Standard No. 109 applies according to its terms to '...tires for use o passenger cars...' We believe it reasonable to distinguish these ASTM test tires from tires subject to Standard No. 109. While physically similar to passenger car tires, these tires are manufactured purely as test devices, and for test purpose. We conclude, therefore, that they are not 'for use on passenger cars' within the meaning of Standard No. 109. These tires should be distinguished from experimental program for passenger car tires, which we have found to be subject to Standard no. 109.; Because of this conclusion, there are no NHTSA prohibitions on th tires' use as test tires. They may be used for testing purposes on public highways and airport runways if that testing can be conducted in a safe manner. You should, however, check State and local laws in any area in which you which to conduct testing to see that those laws permit testing if this type. Because the tires are not subject to Standard No. 109 we believe it would be preferable if they did not contain the nomenclature required by Standard No. 109 except insofar as that nomenclature relates to their safe use in testing. This would reduce the chance that they may be used on passenger cars for other than test purposes. We also believe a stronger warning against general use would be proper. We have in mind Something like 'CAUTION: NOT FOR GENERAL HIGHWAY USE - DO NOT USE EXCEPT FOR SPECIAL TEST PURPOSES.'; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3729OpenMr. C. B. Bright, Jr., C. B. Bright Motor Co., Route 1, Ashland, MS 38603; Mr. C. B. Bright Jr. C. B. Bright Motor Co. Route 1 Ashland MS 38603; Dear Mr. Bright: This is in reply to your letter of July 19, 1983, to Mr. Vinson of thi office. You have asked whether you are violating any Federal standards or regulations by adding 'right side steering, accelerator, brakes & turn signal controls to rural mail carriers delivery vehicles (cars, pickup, jeeps, etc.).' You have told us that you do not modify in any way the left hand side controls with which the vehicle was originally equipped.; Assuming that your modifications do not affect the performance of an of the systems with which the vehicle was equipped by its original manufacturer, your conversion operations would not be prohibited by the National Traffic and Motor Vehicle Safety Act. However, with respect to any new vehicle that you modify which has not yet reached its first purchaser for purposes other than resale, you are required to affix a label identifying you as the alterer and certifying that the vehicle as altered meets all applicable Federal motor vehicle safety standards. This is required by Title 49 Code of Federal Regulations, Section 567.7. I enclose a copy of Part 567 for your information.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam0806OpenMr. Sam Huff, Specifications Consultant, Associated General Contractors, Texas Highway-Heavy Branch, P. O. Box 2185, Austin, TX 78767; Mr. Sam Huff Specifications Consultant Associated General Contractors Texas Highway-Heavy Branch P. O. Box 2185 Austin TX 78767; Dear Mr. Huff: This is in reply to your letter of July 31, 1972, concerning work to b performed on new trucks. Your three questions are answered below.; You ask, 'What are the legal aspects of a road contractor doing th fifth-wheel work on a new truck?' The installation of a fifth wheel on a new vehicle would most likely make the installer a 'final-stage manufacturer' under NHTSA Certification regulations (49 CFR Part 567) and regulations governing 'Vehicles Manufactured in Two or More Stages' (49 CFR Part 568). Final-stage manufacturers bear the responsibility for certifying that the completed vehicle conforms to all applicable motor vehicle safety standards. The procedure for certifying is specified in the Certification regulations, copies of which are enclosed.; Your second question is, 'At what stage after purchase may a new truc be legally termed a used truck?' For our purposes, a used vehicle is any vehicle that has been purchased in good faith for a purpose other than resale (15 U.S.C. 1397(b)(1)).; Your last question is, 'Would the installation of extra lights o safety items be construed as final manufacturing?' The installation of readily attachable components, such as mirrors or tires, is not considered to be an activity which makes the installer a final-stage manufacturer. We are of the opinion that the same would be true regarding the installation of 'extra' lights (those not required pursuant to Motor vehicle Safety Standard No. 108, (49 CFR 571.108)). We cannot provide you with an opinion as to 'safety items' as this term is too general. However, assuming that you are referring to items not required by a motor vehicle safety standard, our answer would most likely be the same. The manufacturer should determine whether the component he installs affects to a significant extent either the configuration or purpose of the vehicle. If it does not, (we will accept a manufacturer's reasonable determination in this regard) then the installer would not be considered a final- stage manufacturer.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4516OpenMr. Scott A. Snyder 117 South Keesey Street York, PA 17402; Mr. Scott A. Snyder 117 South Keesey Street York PA 17402; "Dear Mr. Snyder: This is in reply to your letter of March l0, l988, t the Department's regional office in Philadelphia, asking for a response concerning 'ornamental lighting.' In your opinion 'a few extra lights on the side and rear of a vehicle would help other people see you better while driving at night.' The agency is interested in the role that vehicle conspicuity plays in accidents and accident avoidance. With reference to motorcycles, we have amended our motor vehicle lighting standard to prescribe performance characteristics for headlamp modulation. We were prepared to amend the standard to require the activation of motorcycle headlamps when the ignition was turned on (but did not do so when we learned that almost all motorcycles were being wired to operate in that fashion). Some time ago we asked the public to comment on ways of increasing the conspicuity of large vehicles as our research had indicated that reflective tape applied to the side and rear of wide trucks and trailers might lessen crashes and crash severity, and our research still continues in this area. Most importantly we adopted the center highmounted stop lamp for passenger cars because of the ability it demonstrated in test fleets to reduce the frequency of rear end impacts. The type of lights of which you speak are referred to as 'presence' lamps (as contrasted with 'signal' lamps), and the agency over the years has acted with respect to all motor vehicles by requiring them to be equipped with side marker lamps, and by increasing the lens area for stop lamps. As the Federal safety standards are by statutory definition 'minimum' safety standards, the requirement that there be two taillamps, for example, does not mean that a manufacturer may not add two more if it wishes, or any lighting device not covered by the standard. The sole restriction is that lighting devices added by the manufacturer or dealer that are in excess of the minimum must not impair the effectiveness of the equipment required by the standard. This could happen, for example, if a fog lamp (not covered by the standard) was of an intensity and located so that it masked an adjacent front turn signal. With respect to nighttime operation, the critical issue would appear to be thatadditional lighting devices not create glare to oncoming and following drivers. The owner of the vehicle is not under a similar Federal restriction, and may personally add such additional lighting devices as seems desirable, subject to the laws of the States where the vehicle is registered and/or driven. However, the owner may not have these devices installed by a motor vehicle dealer or repair business if the result is to render wholly or partially inoperative any of the vehicle's original lamps or reflectors. We appreciate your suggestion for improving motor vehicle safety. Sincerely, Erika Z. Jones Chief Counsel"; |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.