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 |
|---|---|
ID: aiam5060OpenMs. Mindy Lang Division Manager Huntleigh Transportation Services Inc. #12 Millpark Court Maryland Heights, MO 63043; Ms. Mindy Lang Division Manager Huntleigh Transportation Services Inc. #12 Millpark Court Maryland Heights MO 63043; "Dear Ms. Lang: This responds to your letter of September 12, 1992 requesting information on regulations concerning bus conversions. Your company converts the interior of buses by installing such materials as carpets, wall coverings, and blinds. In particular you asked for information on regulations concerning the attachment of seats to vehicles and the material used for the construction of seats. I am pleased to have this opportunity to explain our law and regulations to you. The National Traffic and Motor Vehicle Safety Act (the Safety Act, 15 U.S.C. 1381 et seq.) authorizes this agency to issue Federal motor vehicle safety standards applicable to 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. NHTSA, however, does not approve motor vehicles or motor vehicle equipment, nor do we endorse any commercial products. Instead, the Safety Act establishes a 'self-certification' process under which each manufacturer is responsible for certifying that its products meet all applicable safety standards. NHTSA has exercised its authority to establish one safety standard relevant to seating, Standard No. 207, Seating Systems, which establishes strength and other performance requirements for vehicle seats. However, this standard excludes passenger seats on buses from these performance requirements. There is one other safety standard that could be affected by the work your company performs. Standard No. 302, Flammability of Interior Materials, specifies burn resistance requirements for materials used in motor vehicles, including buses. If your company converts previously certified buses, it could be considered an alterer under our regulations. Under 49 CFR Part 567, Certification, an alterer is defined as: A person who alters a vehicle that has been previously certified ... other than by the addition, substitution, or removal of readily attachable components such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, ... before the first purchase of the vehicle in good faith for purposes other than resale .... If considered an alterer, your company would be subject to the certification requirements of 49 CFR 567.7. These requirements include provisions that the alterer supplement the original manufacturer's certification label, which must remain on the vehicle, by affixing an additional label. The label must state that the vehicle as altered conforms to all applicable Federal motor vehicle safety standards, including Standard No. 302. The label must also state the name of the alterer and the month and the year in which the alterations were completed. Your company would not be subject to the certification requirements of 49 CFR 567.7 if the modifications involve only readily attachable components. However, the modifications would still be affected by section 108(a)(2)(A) of the Safety Act. That section 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. Any violation of this 'render inoperative' prohibition would subject the violator to a potential civil penalty of up to $1,000 for each violation. I hope you find this information helpful. I have enclosed an information sheet for new manufacturers of motor vehicle equipment that briefly explains the responsibilities imposed on manufacturers, and tells how to get copies of the relevant laws and regulations. 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"; |
|
ID: aiam0798OpenMr. Thomas L. Schroeder, Thoroughbred Homes, Inc., P.O. Box 1728, Valdoeta, GA 31601; Mr. Thomas L. Schroeder Thoroughbred Homes Inc. P.O. Box 1728 Valdoeta GA 31601; Dear Mr. Schroeder: This is in response to your inquiry of July 26, 1972, concerning th application of defect reporting requirements to mobile home manufacturers.; Although mobile homes are not specifically mentioned in the Nationa Traffic and Motor Vehicle Safety Act, they are considered to be motor vehicles subject to the Act. Because of their unique characteristics, mobile homes have been categorized as a separate vehicle type, 'mobile structure trailer,' under the motor vehicle safety standards 49 CFR Part 581. 'Mobile structure trailer' is defined in section 571.3 of that part.; The Defect Reports regulations (49 CFR Part 573) apply to manufacturer of all types of motor vehicles, including mobile structure trailers. They require manufacturers to report the number of vehicles manufactured during each calendar quarter. The description of the regulation's requirements in the article you enclosed is somewhat incomplete and accordingly we have enclosed a copy of the regulation for your guidance.; There are no specific forms which we require to be used in th submission of the specified information. Copies of acceptable formats you may wish to use, however, are also enclosed.; Yours truly, Richard B. Dyson |
|
ID: aiam0262OpenMr. Gerald Sagerman, U.S. Agent, TVR Engineering, Ltd., 572 Merrick Road, Lynbrook, NY 11563; Mr. Gerald Sagerman U.S. Agent TVR Engineering Ltd. 572 Merrick Road Lynbrook NY 11563; Dear Mr. Sagerman: This is in response to your letter of October 14, 1970, to the Directo of the National Highway Safety Bureau forwarding information sheets on the TVR Vixen. I am enclosing copies of the Bureau's Consumer Information Regulations (49 CFR Part 575). The substantive provisions, S 575.101 on vehicle stopping distance, S 575.102 on tire reserve load, and S 575.106 on acceleration and passing ability, require the furnishing of specific information in a format which is in the form set out in the regulations. The information sheets which you have provided fall short of these requirements in both form and substance. For example, S 575.101 requires furnishing information on the minimum stopping distance, expressed in feet, for the particular vehicle, from a particular speed, at specified loads, with the braking system in a specified condition. The information provided by you in this regard is incomplete, and is not in the form specified. In addition, the regulations require the information to describe and be valid for each of the vehicles with which it is provided.; Please study the enclosed regulations carefully and forward to u complying consumer information within the near future. Let us know if you need further assistance.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
|
ID: aiam5430OpenMr. Richard J. Quigley 5886-b Fernflat Road Aptos, CA 95003; Mr. Richard J. Quigley 5886-b Fernflat Road Aptos CA 95003; Dear Mr. Quigley: This responds to your request for reconsideration o our July 15, 1994 interpretation letter on Standard No. 218, Motorcycle helmets. In that letter, we stated that a drawing you provided would not meet the requirement in S5.6.1(e) of the standard that motorcycle helmets be labeled with the symbol DOT. You enclosed a new drawing and ask whether it meets S5.6.1(e). The answer is no. The new version of the drawing consists of three figures that you believe constitute the symbol 'DOT.' Your new drawing continues to incorporate a corporate logo in lieu of the letter 'O.' As explained in our July 15, 1994 letter, because the symbol DOT constitutes the manufacturer's certification that the helmet conforms to Standard No. 218, there must be no ambiguity in the symbol. Using the corporate logo in lieu of the letter 'O' introduces ambiguity as to whether the manufacturer has certified the helmet. Thus, the new version of the drawing you provided does not meet S5.6.1(e) of Standard No. 218. I hope this answers your question. Sincerely, John Womack Acting Chief Counsel; |
|
ID: aiam1920OpenMr. Andrew H. Swartz, Johnson, Hogan & Ometer, Post Office Drawer 668, Moneterey, CA 93940; Mr. Andrew H. Swartz Johnson Hogan & Ometer Post Office Drawer 668 Moneterey CA 93940; Dear Mr. Swartz: This is in response to your letter of April 11, 1975, requesting a interpretation of the meaning of 'gross vehicle weight rating.'; The gross vehicle weight rating (GVWR) of a trailer consists of th weight of the empty trailer plus its rated cargo load. The weight of the tractor is not included. The tractor and the trailer are considered as two separate vehicles, each with its own individual GVWR.; The Distributors Association interpretation you cited is correct, bu you appear to have misinterpreted it. In the case of a semi-trailer, a significant portion of the loaded trailer's GVWR may be supported by the tractor's rear axle. Therefore, the trailer's GVWR may be significantly higher than its gross axle weight rating, which is the weight an entire axle system, including tires, wheels, axle, and suspension systems, is capable of supporting.; Please let me know if you need further assistance. Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam0632OpenMr. Harold E. Krause, Vice-President, Zecol Inc., P.O. Box 1100, Milwaukee, Wisconsin 53201; Mr. Harold E. Krause Vice-President Zecol Inc. P.O. Box 1100 Milwaukee Wisconsin 53201; Dear Mr. Krause: In response to your letter of February 28, I enclose a copy of Federa Motor Vehicle Safety Standard No. 116, *Motor Vehicle Brake Fluids*, which became effective March 1, 1972.; Paragraph S5.2 as amended specifies the appropriate labeling fo containers of fluid manufactured on or after March 1. If the labeled on containers in stock do not meet the new requirements, you may affix a conforming gummed label over them.; I recommend that you subscribe to the Federal Register ($25.00 pe year, from Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402). Which contains all Federal regulations as issued or proposed on a daily basis. As a manufacturer in a regulated industry. it is your responsibility to be completely familiar with all applicable regulations. The Superintendent of Documents can also provide you with a subscription service to Federal Motor Vehicle Safety Standards ($8.00 per year), updated as new regulations are issued.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam4108OpenPeter M. Kopanon, Director, Vehicle Inspection Services, Massachusetts Registry of Motor Vehicles, 100 Nashua Street, Boston, MA 02114; Peter M. Kopanon Director Vehicle Inspection Services Massachusetts Registry of Motor Vehicles 100 Nashua Street Boston MA 02114; Dear Mr. Kopanon: This responds to your March 19, 1986 letter to our office concernin Federal preemption of state motor vehicle safety standards for school buses. Previously, you had requested us to clarify the language of section 103(d) of the National Traffic and Motor Vehicle Safety Act. We responded by letter dated March 24, 1986, which explained the phrase 'procured for the State's own use.' Your current letter focuses specifically on requirements for school bus mirrors in Federal Motor Vehicle Safety Standard No. 111, *Rearview Mirrors*, and asks whether Massachusetts could require an additional mirror on school buses owned by the state and its political subdivisions to enhance the view of school bus operator (sic).; The answer to your question is yes. As explained in our March 2 letter, under S103(d) of the Safety Act, a state may establish safety requirements for motor vehicles procured for its own use if such requirements impose the same or higher standard of performance than the Federal standard. The phrase 'higher standard of performance' means that the state standard must not conflict with the Federal standard, but may contain additional or more stringent requirements. Massachusetts may thus require an additional mirror on its school buses that provides greater views of areas in front of and along sides of the bus. This requirement, however, must not conflict with Federal requirements and prevent the school buses from complying with Federal safety standards.; We explained in our March 24 letter that states may not prescrib safety standards for privately-owned school buses transporting children to private and parochial schools that are not identical to the Federal safety standards covering the same aspects of performance. Your current letter asked further about Massachusetts' requirement that school committees (which we understand to be political subdivisions of the state) provide equal pupil transportation to public, private and parochial schools. You asked whether buses procured to fulfill this mandate are 'procured for the state's own use,' even though the buses would be used to transport students to private and parochial schools.; In our opinion, the answer is yes. NHTSA has interpreted the phras 'procured for its own use' to apply to any vehicle intended for transporting the public which is procured by a state or political subdivision thereof. Buses procured by the state to transport students to private and parochial schools are thus 'procured for the state's own use,' and may be required by Massachusetts to have additional mirrors to promote the safety of the school children they carry. We note, of course, that we suggest no position as to the constitutionality of state law.; I hope we have responded to your concerns. Please contact my office i you have further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam3436OpenMr. J. E. Bingham, British Standards Institution, Maylands Avenue, Hemel Hempstead, Herts HP2 4QS, England; Mr. J. E. Bingham British Standards Institution Maylands Avenue Hemel Hempstead Herts HP2 4QS England; Dear Mr. Bingham: This responds to your letter of June 8, 1981, concerning Standard No 209, *Seat Belt Assemblies*. You are correct that my letter of June 1, 1981, on the abrasion test procedure of the standard should have referred to section 5.1(d), instead of to section 5.2(d).; You also suggested that in the process of clarifying the standard' abrasion requirements, the agency should consider possible modifications to sections 4.2(e) and (f) of the standard. In the process of reviewing the abrasion test requirements, the agency will also examine those other sections to determine what changes should be made.; Finally, you raised the issue of whether the standard, as with othe national and international standards, should have a requirement that conditioned webbing must retain a certain percentage of its unconditioned strength and must also meet the minimum strength requirement for unconditioned webbing. The agency is not aware of any data indicating that our current conditioned strength requirements are insufficient.; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam4259OpenFrank E. McCarthy, Executive Vice-President, National Automobile Dealers Association, 8400 Westpark Drive, McLean, VA 22101; Frank E. McCarthy Executive Vice-President National Automobile Dealers Association 8400 Westpark Drive McLean VA 22101; Dear Mr. McCarthy: It has come to our attention that a recent Alabama Supreme Cour decision has led some dealers to question the appropriate certification to make when issuing odometer disclosure statements. Although we have not received any inquiries from your members at this time, we have been contacted by others in the industry. The purpose of this letter is to advise you of the National Highway Traffic Safety Administration's position concerning the certifications to be made on odometer disclosure statements.; Congress found that purchasers rely on mileage as an indicator of th value and condition of vehicles and enacted Title IV of the Motor Vehicle Information and Cost Savings Act, 15 U.S.C. S1981 *et seq*. Section 1988(a) of the Act requires the Secretary of Transportation to prescribe rules requiring any transferor to give a written disclosure (1) of the cumulative mileage registered on the odometer or (2) that the actual mileage is unknown, if the odometer reading is know to the transferor to be different from the number of miles the vehicle has actually travelled. To carry out this mandate, Federal regulation 49 C.F.R. Part 580 was promulgated. Furthermore, Section 1988(a) states that no transferor shall violate any rule prescribed under the section or give a false statement to a transferee in making any disclosure required by such rule.; A Senate report interprets Section 1988 as placing duty on auto dealer to alert purchasers of irregularities in odometers when, in the exercise of reasonable care, they would have reason to know the odometer reading is inaccurate. S. Rep. No. 92-413, (92nd Cong., 2nd Sess.), 1972 U.S. Code Cong. & Ad. News 3971-3972. If a purchaser receives an odometer statement in which his transferor certified that the odometer reading does not reflect the actual mileage and should not be relied upon, that purchaser, when selling the vehicle, should certify the same. However, if a purchaser receives an odometer statement in which his transferor certified that to the best of his knowledge the odometer reading reflects the actual mileage the vehicle has been driven, and he has no reasonable suspicion that the reading is inaccurate, when selling the vehicle, he should not certify that the reading is inaccurate. If transferors certify the reading as inaccurate in the latter situation, it is the position of the National Highway Traffic Safety Administration that they violate the regulations prescribed under Section 1988, 49 C.F.R. S580.4.; The Federal regulations provide for the inclusion of two sets o certifications on odometer disclosure statements. If the dealers truly wish to insulate themselves from liability when they have a reasonable suspicion that the mileage on the odometer has been altered, they *should* certify that the reading is not accurate, and check the third statement in the first set of certifications. However, none of the three statements in the second set covers a situation where a transferor suspects that an odometer reading is inaccurate, but the odometer was not altered, set back or disconnected in his possession. The Agency allows a transferor to check the first statement and cross out the lines which read, 'and I have no knowledge of anyone else doing so' provided that though crossed out it can still be read. Alternatively, we have no objection to a transferor writing and checking a fourth statement which would read:; >>>I hereby certify that the odometer of said vehicle was not altered set back, or disconnected while in my possession.; << |
|
ID: aiam3066OpenMr. D. J. Arneson, Box 141, Southbury, CT 06488; Mr. D. J. Arneson Box 141 Southbury CT 06488; Dear Mr. Arneson: This is in reply to your letter of June 27, 1979, which inquire whether there are any regulations governing the installation of a propane-fueled engine, or the conversion of a gasoline-fueled engine to a propane-fueled engine, in vehicles registered for use on Federal, State, and local highways.; To date, the National Highway Traffic Safety Administration (NHTSA) ha not exercised its authority pursuant to the National Traffic and Motor Vehicle Safety Act, as amended 1974 (15 U.S.C. 1381 *et seq*.) (the Act), to issue a safety standard applicable to propane-powered vehicles. Federal Motor Vehicle Safety Standard No. 301-75, *Fuel System Integrity*, applies only to vehicles which use fuel with a boiling point above 32 degrees F., and propane has a boiling point well below this temperature. Despite the absence of safety standards specifically applicable to propane-powered engines, however, an installer of these systems may be subject to other Federal requirements.; Under NHTSA safety regulations, a person who alters a new vehicle prio to its first purchase in good faith for purposes other than resale is required to attach an additional label to the vehicle certifying that, as altered, the vehicle remains in compliance with all applicable safety standards (49 CFR 567.7). This requirement would apply to a person who alters a new vehicle to install a propane fuel system. (See the enclosed pamphlet listing the Federal motor vehicle safety standards and an information sheet explaining where to obtain copies of the standards.) Additionally, should a noncompliance or safety-related defect be discovered in such a vehicle, as a result of the modification, the alterer could be liable for a civil penalty unless he or she could establish that he or she did not have actual knowledge of the noncompliance and that he or she did not have reason to know in the exercise of due care that the vehicle did not comply. (Section 108(b)(2)) Defects in the propane-fueled engines or in components used for converting a gasoline-fueled engine would be the responsibility of their manufacturers, regardless of whether they were installed in new or used vehicles. Upon discovery of a safety-related defect by either the Secretary of Transportation, the NHTSA Administrator or the manufacturer himself, the manufacturer would be required to notify vehicle owners, purchasers, and dealers and provide a remedy for the defect.; A person who installs a propane- fueled engine or converts th gasoline-fueled engine in a used vehicle is not required to affix an alterer's label. However, if that person is a manufacturer, distributor, dealer, or motor vehicle repair business, he must not in the course of installing the propane components knowingly render inoperative any device or element of design originally installed in the vehicle in compliance with applicable Federal motor vehicle safety standards. (Section 108(a)(2)(A) of the Act); I hope that you will find this response helpful and have not bee inconvenienced by our delay in sending it to you.; 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.