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: aiam3866OpenMr. Brian Gill, Senior Manager, Certification Department, American Honda Motor Co., Inc., P.O. Box 50, Gardena, CA 90247; Mr. Brian Gill Senior Manager Certification Department American Honda Motor Co. Inc. P.O. Box 50 Gardena CA 90247; Dear Mr. Gill: This is in response to your letter of May 25, 1984, asking for a interpretation of Motor Vehicle Safety Standard No. 108. Table IV specifies that the minimum horizontal separation distance '(centerline to centerline of lamp)' for rear turn signal lamps on motorcycles is 9 inches. You have asked whether the 'centerline' refers to the distance between the lens centers, between the centers of the effective projected luminous areas, or between the bulb centers.; You asked for confirmation of your belief that the prope interpretation is found in the referenced SAE Standard, J588e, which contains the language 'Optical axes (filament centers),' implying that the correct distance is that between the 'bulb centers' as you term it.; We find no direct correlation between the phrases 'centerline t centerline of lamps' and 'optical axis (filament center).' The lamp is a device emitting light whereas 'optical axis (filament center)' does not refer to the lamp but only to a portion of its light-producing component. As that phrase is used in SAE J588e, it defines the method of measuring distances between bulbs in multi-compartment lamps for the purpose of testing for photometric requirements (paragraph 3.1), or in measuring the separation of the turn signal from the headlamp (paragraph 4.2, where, incidentally, it is expressed as the distance between filament and a lamp component, the retaining ring).; Taken literally, 'centerline to centerline of lamps' in our view mean the distance between lens centers. In the response to petitions for reconsideration of the center high-mounted stoplamp amendment (May 17, 1984), the question was asked whether the 'center' of the lamp was its geometric center, its optical center, or the center of the bulb filament. The agency replied that the center of the lamp is the geometric center. Since the purpose of the minimum separation requirement is to insure that the turn signal is perceived as such, we believe that the correct interpretation of 'centerline to centerline' is a measurement from the geometric center of one lamp to the geometric center of the other lamp. The geometric center would be synonymous with the term 'geometric centroid of lens' as used in SAE J1221 *Headlamp-Turn Signal Spacing*.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1614OpenMr. Robert S. Podlewski, Brake Engineer, Diamond Reo Trucks, Inc., 1331 S. Washington, Lansing, MI 48920; Mr. Robert S. Podlewski Brake Engineer Diamond Reo Trucks Inc. 1331 S. Washington Lansing MI 48920; Dear Mr. Podlewski: This responds to your August 13, 1974, question whether building motor vehicle from a used power train (rear axle, suspension, drive line, and engine) and a new 'glider kit' constitutes the manufacture of a new motor vehicle, subject to Federal motor vehicle safety standards, including Standard No. 121 after March 1, 1975. Typically, a 'glider kit' is a truck chassis on which a cab and front axle system are mounted, which is purchased to permit the re-utilization of a power train from another vehicle.; Re-use of components from an existing vehicle in the construction o another vehicle may or may not result in the manufacture of a new vehicle. The NHTSA has established that the addition of new components (such as truck body) to the chassis of a used vehicle does not constitute the manufacture of a new vehicle. Conversely, the addition of used components to a new chassis which has never been certified in a vehicle constitutes the manufacture of a new vehicle, subject to the safety standards in effect for that vehicle class on the date of manufacture. This criterion has been relied on in the area of chassis-cab multistage manufacture.; Since a glider kit typically incorporates a new chassis (as well as new cab and front suspension), the NHTSA finds that the use of such a glider kit in the construction of a motor vehicle constitutes the manufacture of a new motor vehicle. To conclude otherwise would mean that a vehicle composed entirely of brand new components except the rear axle and perhaps the engine and transmission, would qualify as a used vehicle.; You noted that our decision could eliminate the use of glider kit because Standard No. 121 certification would prevent re-use of rear axles which do not meet 121-level performance requirements. We believe that our determination will contribute to motor vehicle safety by introducing more 121-type vehicles on the highway and will not interfere with the use of glider kits in the long term. Glider kits can be made to meet Standard No. 121 as soon as 121-type rear axles become available on the used market. Until that time, the rear axles of present vehicles may be utilized as replacement parts in used vehicles which are not required to meet Standard No. 121.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam1617OpenMr. Robert S. Podlewski, Brake Engineer, Diamond Reo Trucks, Inc., 1331 S. Washington, Lansing, MI 48920; Mr. Robert S. Podlewski Brake Engineer Diamond Reo Trucks Inc. 1331 S. Washington Lansing MI 48920; Dear Mr. Podlewski: This responds to your August 13, 1974, question whether building motor vehicle from a used power train (rear axle, suspension, drive line, and engine) and a new 'glider kit' constitutes the manufacture of a new motor vehicle, subject to Federal motor vehicle safety standards, including Standard No. 121 after March 1, 1975. Typically, a 'glider kit' is a truck chassis on which a cab and front axle system are mounted, which is purchased to permit the re-utilization of a power train from another vehicle.; Re-use of components from an existing vehicle in the construction o another vehicle may or may not result in the manufacture of a new vehicle. The NHTSA has established that the addition of new components (such as a truck body) to the chassis of a used vehicle does not constitute the manufacture of a new vehicle. Conversely, the addition of used components to a new chassis which has never been certified in a vehicle constitutes the manufacture of a new vehicle, subject to the safety standards in effect for that vehicle class on the date of manufacture. This criterion has been relied on in the area of chassis-cab multistage manufacture.; Since a glider kit typically incorporates a new chassis (as well as new cab and front suspension), the NHTSA finds that the use of such a glider kit in the construction of a motor vehicle constitutes the manufacture of a new motor vehicle. To conclude otherwise would mean that a vehicle composed entirely of brand new components except the rear axle and perhaps the engine and transmission, would qualify as a used vehicle.; You noted that our decision could eliminate the use of glider kit because Standard No. 121 certification would prevent re-use of rear axles which do not meet 121-level performance requirements. We believe that our determination will contribute to motor vehicle safety by introducing more 121-type vehicles on the highway and will not interfere with the use of glider kits in the long term. Glider kits can be made to meet Standard No. 121 as soon as 121-type rear axles become available on the used market. Until that time, the rear axles of present vehicles may be utilized as replacement parts in used vehicles which are not required to meet Standard No. 121.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1987OpenMr. J. W. Boyd, Manager, Government & Industry Technical Relations, Dunlop Tire and Rubber Corporation, Box 1109, Buffalo, NY 14240; Mr. J. W. Boyd Manager Government & Industry Technical Relations Dunlop Tire and Rubber Corporation Box 1109 Buffalo NY 14240; Dear Mr. Boyd: This is in response to your letter of July 1, 1975 (NA-2637A) forwarded to us by the Tire Division, which requests comments on the issues raised by two letters from Mr. R. G. Clifton of Dunlop U.K.; Mr. Clifton's first concern is with respect to the prope interpretation of section 159(2) of the 1974 amendments to the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1419). Section 159 provides that the definitions of 'original equipment' and 'replacement equipment' in section 159 may be changed 'as otherwise provided by Regulations of the Secretary.' This phrase does not mean that the definitions may be changed by *any* regulation, but rather that the definitions may be changed by a regulation implementing sections 151-60 of the 1974 amendments, to which the provisions of section 159 specifically apply. Therefore, a definition of 'tire manufacturer' in a regulation issued pursuant to some other statutory provision has no effect on the definitions of 'original equipment' and 'replacement equipment' in section 159. No specific regulation has yet been issued by the National Highway Traffic Safety Administration (NHTSA) modifying the provisions of section 159, although such a regulation is currently under consideration.; Mr. Clifton's second concern was that no amendments to Part 573 hav been proposed in order to make tire and equipment manufacturers subject to defect reporting requirements, as required by the 1974 amendments. The NHTSA is preparing to issue proposed amendments to Part 573 which will reflect this requirement.; Mr. Clifton's third concern, expressed in his letter of June 3, wa that section 159(2)(D) of the 1974 amendments would make the motor vehicle manufacturer totally responsible for the original equipment tires on his vehicles. Although section 159 places the legal responsibility for notification and remedy of safetyrelated (sic) defects in original equipment on the vehicle manufacturers, it does not lessen the obligation of the tire manufacturers to ensure that their tires contain no safety-related defects. Tire manufacturers do have an obligation to notify of and remedy defects in tires used as replacement equipment.; We trust this has been helpful. If you have any further questions please do not hesitate to write.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4208OpenMrs. Bettie Lou Simcox, 10 Martin Place, Little Falls, NJ 07424-1709; Mrs. Bettie Lou Simcox 10 Martin Place Little Falls NJ 07424-1709; Dear Mrs. Simcox: This is in reply to your letter of August 28, 1986, to Taylor Vinson o this Office regarding the acceptability of an aftermarket stop lamp intended for installation on motorcycles. The product is a stop lamp that, when the brake is applied, pulses before going into a steady- burning mode. The New Jersey Department of Motor Vehicles has informed you that stop lamps are required by Federal law to be steady-burning. A representative of this agency has told you that such a lamp would be acceptable as a supplementary stop lamp, but not as a replacement lamp. You are writing us for confirmation of the Federal requirement.; Your understanding is essentially correct. Federal Motor Vehicle Safet Standard No. 108 *Lamps, Reflective Devices, and Associated Equipment* requires most vehicle lamps, including stop lamps, to be steady- burning in use, though signal lamps such as turn signals and hazard warning signals must flash. Further, the replacement of an original equipment steady-burning stop lamp with one that flashes before becoming steady-burning would be considered a violation of the National Traffic and Motor Vehicle Safety Act if performed by a manufacturer, distributor, dealer, or motor vehicle repair business, though not if performed by the owner of the vehicle. As for the acceptability of the device as a supplementary stop lamp, Standard No. 108 really does not contemplate a supplementary stop lamp for motorcycles. Although requiring at least one stop lamp, the standard allows two provided that they 'are symmetrically disposed around the vertical centerline.' We interpret this as meaning that a second stop lamp must be identical in all respects to the first one, for surely a confusing situation would result if stop lamps on either side of the vertical centerline were unequal in size or in method of operation. However, the flashing/steady burning stop lamp mounted on the vertical centerline would be permissible as an addition to motorcycle stop lamp systems consisting of two lamps mounted on either side of the vertical centerline. Alternatively, if you wished to add two pulsing stoplamps mounted symmetrically around the vertical centerline in addition to the steady-burning original equipment stoplamp, that also would be permissible.; We appreciate your interest in motorcycle safety, and your taking th time to write us of your concerns.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam5132OpenMs Beverley Silver-Corber 6738 Montgomery St. Vancouver, B.C. V6P 4G4; Ms Beverley Silver-Corber 6738 Montgomery St. Vancouver B.C. V6P 4G4; "Dear Ms Silver-Corber: This is in reply to your letter to the agenc with respect to your wish to import into the United States a l992 Honda Accord, which was not manufactured to conform to the automatic restraint requirements of U.S. Federal Motor Vehicle Safety Standard No. 208 Occupant Crash Protection. You would like to use the car for a two-year period in the U.S. while your husband is in graduate school. You have asked whether you qualify for an exemption, and whether you will be allowed to import the car for the two years of study. Under regulations of the Department of Transportation that govern the importation of motor vehicles, you, as a nonresident of the United States, are permitted to import your nonconforming Honda for a period of up to one year, provided that the importation is for your personal use, that you will not sell it during that time, and that the vehicle will be exported not later than the end of one year after entry (Title 49, Code of Federal Regulations, Section 591.5(d)). The reason for the one-year limitation is that, under the Road Traffic Convention (1952) and the Customs Convention on the Temporary Importation of Private Road Vehicles (1957), Conventions to which the United States is a party, an imported vehicle may be subjected to all the laws of any country in which it has remained longer than one year, including import duties and taxes. In recognition of the effect of these Conventions, we have adopted a one-year limitation on the temporary importation of nonconforming vehicles by nonresidents, and we do not grant waivers or exemptions from this requirement. However, if you return in the Honda to Canada at the end of the first year of your husband's studies, we would regard the export provisions as having been met, and a new one-year period would begin when the car is re-imported into the U.S. for your husband's second year of studies. Although our regulations do provide for indefinite entry of nonconforming vehicles that are imported for 'research, investigations, studies, demonstrations or training' (Section 591.5(j)), we do not interpret this as applying to importers who come to the U.S. to study. Rather, it applies to the importer who wishes to import a vehicle so that it may be studied. Sincerely, John Womack Acting Chief Counsel"; |
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ID: aiam3574OpenJames Marshall Smith, Esq., Legal Aid of Western Missouri, 1103 Grand Avenue, Kansas City, MO 64106; James Marshall Smith Esq. Legal Aid of Western Missouri 1103 Grand Avenue Kansas City MO 64106; Dear Mr. Smith: This is in response to your letter of June 10, 1982, concerning whethe the odometer disclosure statement on the Missouri certificate of title has been approved for use in lieu of the Federal odometer disclosure statement.; The Motor Vehicle Information and Cost Savings Act ('Act') (15 U.S.C S1981 *et seq*.) prohibits the disconnection, resetting or alteration of a vehicle odometer with the intent to change the number of miles. The Act also requires that a written disclosure of the mileage registered on the odometer be provided by the seller to the buyer at the time ownership of a vehicle is transferred. 15 U.S.C. S1988. Each dealer or distributor of a motor vehicle is required by law to retain for four years a copy of each odometer statement he issues and receives. Odometer Disclosure Requirements ('regulations') (49 CFR Part 580).; The Odometer Disclosure Requirements provide that the transferor of vehicle may make the disclosure required by the Federal odometer laws on the state certificate of title, if the state title document contains essentially the same information required on the Federal odometer disclosure statement. If the information contained on the state certificate of title varies from that required by the Federal form, the state must obtain the approval of this agency before its certificate of title can be used as a substitute for the Federal form.; In order to spare states the burden of an approval process the agenc has indicated that certain variations from the Federal form are acceptable. In the *Federal Register* notice of August 1, 1977, which amended the disclosure regulation, we gave examples of shortened forms that would be acceptable.; A state document can be considered to be approved for use as a ful disclosure statement if it varies from the Federal form in only those aspects noted in the August 1, 1977, notice, a copy of which is enclosed.; Missouri has not submitted its certificate of title to the agency fo approval as a substitute for the Federal odometer disclosure statement so, therefore, the agency does not know whether Missouri's certificate of title can be substituted for the Federal odometer disclosure statement.; If you have any further questions, please do not hesitate to write. Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam5028OpenMr. Joe Wos A & D Lock & Key 238 Faithway Dr. Seffner, FL 33584; Mr. Joe Wos A & D Lock & Key 238 Faithway Dr. Seffner FL 33584; Dear Mr. Wos: This responds to your May 26, 1992 letter asking whethe it is 'legal to repair an automobile that has an airbag deployed and not put the air bag back in.' I am enclosing a copy of a January 19, 1990 letter to Ms. Linda L. Conrad, that explains whether a used car dealer has an obligation to replace a deployed air bag prior to selling the car. The same statutory and regulatory considerations that applied to that situation would apply to the replacement of a damaged air bag steering column (after the air bag has deployed) with a steering column without an air bag. 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, Paul Jackson Rice Chief Counsel Enclosure; |
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ID: aiam3008OpenMr. Teruo Maeda, General Manager, Nissan Motor Co., Ltd., Engineering Office of North America, P.O. Box 1606, 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Teruo Maeda General Manager Nissan Motor Co. Ltd. Engineering Office of North America P.O. Box 1606 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Maeda: This is in response to your letter of April 19, 1979, asking whether tie down hook located beneath a vehicle between the rear main body and the rear bumper is considered a vehicle exterior surface for purposes of section 581.5(c)(10) of the Part 581 Bumper Standard (49 CFR 581.5(c)(10)). You state that this component may experience some paint separation on contact with the vehicle bumper face bar during pendulum and barrier impact testing.; >>>Section 581.5(c)(10) provides that, 'For vehicles manufactured on or after September 1, 1979, the exterio surfaces, except the bumper face bar, shall have no separations of surface materials, paint, polymeric coatings, or other materials from the surface to which they are bonded ...'<<<; when subjected to the specified pendulum and barrier tests. A component located on the vehicle underbody behind the bumper face ba is not an exterior surface for purposes of section 581.5(c)(10). For this reason, the tie down hook you describe would not be subject to the requirements of that section.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam3457OpenMr. Dennis E. Sekermestrovich, Sales Manager, Composite Cylinder Division, Luxfer USA Limited, P.O. Box 5300, Riverside, CA 92507; Mr. Dennis E. Sekermestrovich Sales Manager Composite Cylinder Division Luxfer USA Limited P.O. Box 5300 Riverside CA 92507; Dear Mr. Sekermestrovich: This responds to your letter of July 2, 1981, seeking confirmation tha DOT approval is not required for compressed gas tanks that are to be used as part of an automobile fuel system.; Your determination that DOT approval is not required is correct. Th National Highway Traffic Safety Administration issues, pursuant to the National Traffic and Motor Vehicle Safety Act, safety standards and regulations governing the manufacture of motor vehicles and motor vehicle equipment. However, the agency does not pass approval on any vehicle or piece of equipment prior to its introduction in the market place. It is up to the manufacturer to certify, on the basis of due care, that its vehicles or equipment comply with all applicable Federal motor vehicle safety standards.; We note that the term 'manufacturer' is defined by section 102(5) o the National Traffic and Motor Vehicle Safety Act as 'any person engaged in the manufacturing or assembling of motor vehicles or motor vehicle equipment, *including any person importing motor vehicles or motor vehicle equipment for resale*.' Emphasis added. The agency's enforcement program is based on compliance testing of vehicles or equipment that have already been certified by the manufacturer.; We are enclosing for your information a discussion which sets forth th implications under Federal law of converting gasoline-powered vehicles to use propane or other gas, as well as a general discussion of auxiliary fuel tanks. From that discussion, you will see that there are no safety standards directly applicable to propane fuel tanks as pieces of automobile equipment. There are, however, specifications under the Bureau of Motor Carrier Safety regulations relating to propane fuel systems on commercial vehicles or to tanks used for shipment of propane gas in interstate commerce. If your tanks will be used on other than private vehicles, these regulations may be of interest to you. For further information, you may contact Mr. W. R. Fiste of the Bureau of Motor Carrier Safety (202-426-0033).; We have also enclosed, at your request, copies of Safety Standard No 301, *Fuel System Integrity*, and 49 CFR Part 567, *Certification*.; Sincerely, Frank Berndt, 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.