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: aiam1336OpenMr. R.O. Crider, Manager, Government Safety Standards and Regulations Compliance, Fruehauf Corporation, P.O. Box 238, Detroit, MI 48232; Mr. R.O. Crider Manager Government Safety Standards and Regulations Compliance Fruehauf Corporation P.O. Box 238 Detroit MI 48232; Dear Mr. Crider: Thank you for your letter of November 20, 1973, asking whether you ma install 'lights as set forth in Example 1.' In this example identification lamps would be mounted under the rear crossmember of the vehicle while 'the combination tail and turn signal lamps (at the bottom) could serve as the clearance lamps.'; The rear lighting scheme shown in your 'Example 1' appears to b seriously at variance with Standard No. 108. There is a clear violation of paragraph S4.4.1 which forbids the optical combination of tail lamps and clearance lamps. Both clearance lamps and identification lamps must be located 'as close as practicable to the top of the vehicle.' The fact that you have developed a clearance lamp that can be mounted in the header area demonstrates that that is the 'practicable' location, despite the fact that the header may be too shallow to accommodate the lamps specified by the customer. Further, since the performance required of clearance lamps is identical to that for identification lamps, and three of your clearance type lamps could serve as identification lamps, the header would appear to be the 'practicable' location for the identification lamp arrangement as well.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam4134OpenMr. Bob Quick, 1830 North Ridge Street, Coralville, IA 52241; Mr. Bob Quick 1830 North Ridge Street Coralville IA 52241; Dear Mr. Quick: Thank you for your recent telephone call in which you asked whether i would be legally permissible for an odometer which is being installed in your automobile to replace one that was registering high mileage to be set at the mileage that the automobile was actually driven. There is regrettably no means for this to be done under the Federal odometer law. Section 407 of the Motor Vehicle Information and Cost Savings Act, as found in 15 U.S.C. 1987, permits the 'replacement of an odometer, provided the mileage indicated thereon remains the same as before the . . . replacement.' No adjustments are permitted to compensate for any excess mileage that may have registered on the odometer being replaced. Although some may regard this as being unduly stringent, the creation of such a loophole could invite fraudulent abuse and seriously undermine the effectiveness of our odometer enforcement program.; Enclosed for your information is a copy of the statute and regulation that establish odometer requirements, together with a fact sheet that we have prepared on the subject.; If we can be of any further assistance, please feel free to contact u again.; Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam2849OpenMr. F. Michael Petler, Assistant Manager, Safety & Legislation Dept., U.S. Suzuki Motor Corporation, 13767 Freeway Drive, Santa Fe Springs, CA 90670; Mr. F. Michael Petler Assistant Manager Safety & Legislation Dept. U.S. Suzuki Motor Corporation 13767 Freeway Drive Santa Fe Springs CA 90670; Dear Mr. Petler: This is in reply to your letter of August 10, 1978, asking for a interpretation of Motor Vehicle Safety Standard No. 108. You have asked 'whether an aftermarket Class A reflex reflector can be installed in addition to the original Equipment Class A reflex reflector, that is, an existing part of the motorcycle's rear combination lamp assembly.' You have stated that 'both reflectors would be installed vertically on the motorcycles vertical centerline,' and have commented that you understand 'that two reflectors may be installed horizontally about the vertical centerline, but it is unclear to us whether they may both be installed one on top of the other, vertically, as this is not addressed in FMVSS No. 108.'; You have misunderstood Standard No. 108. Table IV clearly states wit respect to location of rear reflex reflectors on motorcycles that 'if two are used on the rear, they shall be symmetrically disposed about the vertical centerline.' This requirement precludes the use of two rear reflectors mounted above each other vertically on the vehicle's centerline if your fender extension is sold as an accessory on a motorcycle at the time of its first purchase for purposes other than resale.; Generally, however, Federal standards do not cover vehicles after thei first purchase and an owner may modify his vehicle in any manner he chooses consistent with local law. Modification by dealers, distributors, and repair businesses are prohibited only if they 'render inoperative' any device or element of design installed on a motor vehicle in accordance with a Federal safety standard. Although aftermarket installation of the fender with reflector by a dealer after a vehicle's sale would not be consistent with the reflector location requirements of Standard No. 108, we cannot say that it would 'render inoperative' the reflector installed as original equipment. We therefore have no objection to you offering this component as an aftermarket accessory to be added after a vehicle's initial sale.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam0874OpenMr. E.T. Brodie, Bandag, Incorporated, 1056 Hershey Road, Muscatine, Iowa 52761; Mr. E.T. Brodie Bandag Incorporated 1056 Hershey Road Muscatine Iowa 52761; Dear Mr. Brodie: In your letter of September 27 you suggest that Standard 117 paragraph 5.2.1(b) which relates to exposing fabric during the buffing operation of the retread process might be interpreted as forbidding the retreading of casings containing nail holes. You further quote the conclusion of an outside contractor of a Department of Transportation sponsored tire repair study that 'while test wheel tests could be passed on repaired tires, road test showed them all to be satisfactory.'; We do not consider nail holes to constitute and exposure of cord fabri within the meaning of the standard. Briefly, our examination of retread tires to date shows that nail holes which have been repaired with the repair materials vulcanized to the inside of the tire are very satisfactory. We have cut through such repairs and find them to be sound even after being subjected to Federal Motor Vehicle Safety Standards No. 109 and No. 117, Endurance and High Speed Wheel Tests. Provided the nail holes are permanently sealed on the inside of the tire they appear to be no more objectionable than the casing penetrations made by new tire manufacturers and retreaders in their awl venting procedures.; The Discussion Paper presented at the National Highway Traffic Safet Administration Technical Meeting held on April 10, 1969, contained rather detailed requirements for casings that were to be retreaded. Included within this extensive list were requirements for not retreading a casing if 'two closed punctures (nail hole type) which extend through the fabric, or are less then 15 inches apart or are outside if the tread area.' As a result of the comments received at the April 10, 1969, technical conference, at which you and Mr. Vischer attended, the Administration changed the casing condition requirements to only prohibit retreading of casing which had cord or bead wire exposed. The Administration considers the casing as part of the raw material used in the retreading process and as such, each retreader must use his expertise in casing selection prior to applying his DOT self-certification symbol.; Supplementing the above, we have noted that repairs with the repai materials not bonded to the carcass loosen during flexing and have a high incidence of failure on the Endurance and High Speed Wheel Tests.; Sincerely, E.T. Driver, Director, Office of Operating Systems, Moto Vehicle Programs; |
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ID: aiam1766OpenMr. John T. Clark,GENALCO, Inc.,322 Reservoir Street,Needham Heights, Massachusetts 02194; Mr. John T. Clark GENALCO Inc. 322 Reservoir Street Needham Heights Massachusetts 02194; Dear Mr. Clark:#Please forgive the delay in responding to your lette of September 19, 1974, requesting a 'manufacturers designation' for the air brake hose assemblies which you manufacture.#S5.2.4(b) of Federal Motor Vehicle Safety Standard No. 106-74, *Brake Hoses*, was amended on January 29, 1974 (39 FR 3680, Docket No. 1-5, Notice 9), and again on February 26, 1974 (39 FR 7425, Docket No. 1-5, Notice 10).#In place of an assemble's code number, assigned by the National Highway Traffic Safety Administration, S5.2.4(b) of the standard now requires:#>>>A designation that identifies the manufacturer of the hose assembly, which shall be filed in writing with: Office of Standards Enforcement, 'Brake Hose Identification,' National Highway Traffic Safety Administration, 400 Seventh Street S.W., Washington, D.C. 20590. The marking may consist of a designation other than block capital letters required by S5.2.4.<<<#The designation, 'GENALCO, INC.', as depicted in your letter, already satisfies this requirement. This designation is now on file in the Office of Standards Enforcement.#Please note that the symbol DOT and the date of assembly are still required by the third sentence of S5.2.4 to appear in block capital letters and numerals at least one-eighth of an inch high. Please note also that use of the band is required on assemblies manufactured on or after March 1, 1975, and prohibited on assemblies manufactured before that date.#Yours truly,Richard B. Dyson,Acting Chief Counsel; |
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ID: aiam4564OpenMr. Tracy L. Clark, Jr. Vice President Cottle Industries 1103 Musser St. Muscatine, Iowa 52761; Mr. Tracy L. Clark Jr. Vice President Cottle Industries 1103 Musser St. Muscatine Iowa 52761; "Dear Mr. Clark: Thank you for your letter in which you requeste confirmation of your company's status as an alterer of motor vehicles, pursuant to 49 CFR Part 567.7. You stated that your company, Cottle Industries, takes a new Honda moped that is certified as complying with all applicable safety standards, removes the plastic body shell and seating components, and adapts the vehicle for the use of wheelchair riders. Now called the Chariot, the modified moped allows the wheelchair bound to gain access to public roads and highways without having to ride in vans. You assert that the Honda front end and drive train components continue to retain their integrity. You enclosed a brochure describing the Chariot. I am pleased to have this opportunity to explain our regulations to you. Some background information on Federal motor vehicle safety laws and regulations may be helpful. As you are aware, our agency is authorized, under the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1381 et seq., Safety Act), to issue safety standards applicable to new motor vehicles and certain items of motor vehicle equipment. 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. Based on the facts set forth in your letter, it appears that Cottle Industries would be considered an alterer for the purposes of Part 567, Certification (copy enclosed). Alterers that are required to affix certification labels in accordance with 567.7 are defined in that section as follows: A person who alters a vehicle that has previously been certified in accordance with 567.4 or 567.5, 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, shall allow the original certification label to remain on the vehicle, and shall affix to the vehicle an additional label of the type and in the manner and form described in 567.4, containing the following information: * * * * * Cottle Industries does alter previously certified vehicles (the Honda mopeds) before the first purchase of the mopeds in good faith for purposes other than resale. The only conditions in which Cottle would not be required to affix its own certification labels to each moped that it modifies would be: 1. The modifications consisted solely of 'readily attachable components,' or 2. The modifications were only 'minor finishing operations.' Based on the information you have provided, neither of these exceptions would apply in your company's case. Your company cuts the frame of the Honda moped being modified into two sections and then welds those sections to a new tubular steel frame. This new steel frame for the vehicle is not a 'readily attachable component.' Similarly, the operations performed by your company on the Honda mopeds appear to be far more sophisticated than 'minor finishing operations.' Accordingly, Cottle Industries appears to be an alterer subject to the requirements of 49 CFR 567.7. In this case, 567.7 requires that: (1) The alterer supplement the existing manufacturer certification label by affixing an additional label stating that the vehicle as altered conforms to all applicable Federal motor vehicle safety standards as well as stating the firm or individual name of the alterer and the month and the year in which the alterations were completed (see 567.7(a)), (2) The modified values for the vehicle be provided as specified in 567.4(g)(3) and (5), if the gross vehicle weight ratings or any of the gross axle weight ratings of the vehicle as altered are different from those shown on the original certification label (see 567.7(b)), and: (3) The type classification be provided, if the vehicle as altered has a different type of classification from that shown on the original certification. In addition to these certification requirements, an alterer is considered a 'manufacturer' for the purposes of the Safety Act. Among other things, this means an alterer is responsible for notification and remedy of defects related to motor vehicle safety and noncompliances with applicable Federal motor vehicle safety standards, as specified in sections 151-160 of the Safety Act, and alterers are subject to the requirements of 49 CFR Part 573, Defect and Noncompliance Reports. For the purposes of our safety standards, the Chariot would appear to be classified as a 'motorcycle.' A 'motorcycle' is defined at 49 CFR 571.3 as 'a motor vehicle with motive power having a seat or saddle for the use of the rider and designed to travel on not more than three wheels in contact with the ground.' I am enclosing a publication entitled 'Federal Vehicle Safety Standards and Procedures,' which indicates those standards that apply to motorcycles. I am also enclosing a general information sheet for new manufacturers that gives a general description of the applicable regulations, and explains how to get copies of those regulations. You also indicated that your company plans to leave in place on the altered vehicles the vehicle identification number (VIN) originally assigned by Honda to the vehicles. Standard No. 115, Vehicle Identification Number - Basic Requirements (49 CFR 571.115) applies to all motorcycles. Section S4.1 of Standard No. 115 provides in part that: 'Vehicle alterers, as specified in 49 CFR 567.7, shall utilize the VIN assigned by the original manufacturer of the vehicle.' Accordingly, your company as an alterer is required to leave in place the VINs originally assigned by Honda. If you have any further questions or need additional information on this subject, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel Enclosures"; |
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ID: aiam3075OpenMr. Robert J. Crail, Director of Engineering, The Berg Manufacturing Company, P.O. Box 368, Iola, KS 66749; Mr. Robert J. Crail Director of Engineering The Berg Manufacturing Company P.O. Box 368 Iola KS 66749; Dear Mr. Crail: This responds to your June 28, 1979, letter asking several question about the compliance of your trailers with Standard No. 121, *Air Brake Systems*.; You first ask whether section S5.6.3 allows the use of service air t apply the parking brakes as long as a source of energy to apply the parking brakes is available at all times and is unaffected by any single failure in the service brake system. The answer to this question is yes. On August 9, 1979, the agency published in the Federal Register a notice amending section S5.6.3 of the standard to permit the type of parking brake system that you outlined in your letter.; In your second question, you ask whether your braking system complie with section S5.2.1.1. That section requires that a reservoir be provided that is capable of releasing the vehicle's parking brakes and that is unaffected by the loss of pressure in the service brake system. Your trailer has a tank and valve for each axle. You state that in the event of a service system failure including a failure of one of the tanks, that a reservoir is available such that when the supply line is pressurized to 55 psi, the vehicle's parking brakes will release. Assuming that your system operates as you have detailed in your letter, the agency concludes that it complies with S5.2.1.1 of the standard.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1048OpenMr. Normal E. Randall, Manager Quality Control, Joan Fabrics Corporation, 122 Western Avenue, Lowell, MA, 01853; Mr. Normal E. Randall Manager Quality Control Joan Fabrics Corporation 122 Western Avenue Lowell MA 01853; Dear Mr. Randall: This is in reply to your letter of February 28, 1973, and an attache copy of an earlier letter dated September 26, 1972, that you sent to Mr. Bobby A. Boaz in our Office of Consumer Affairs and Public Information but was evidently never received. You ask what types of vehicles are covered by Standard No. 302, 'Flammability of Interior Materials', and especially whether campers, motor homes, and mobile homes are covered.; The standard applies to passenger cars, multipurpose passenge vehicles, trucks, and buses. It does not apply to trailers, the vehicle category which includes mobile homes and other towed recreational vehicles, but it does apply to motor homes and to those campers that are constructed on new chassis.; You ask further for any available information regarding testin procedures, requirements, reporting procedures, and any other related information. There are no reporting requirements, and otherwise the information you seek is found in Standard No. 302 itself. Accordingly, a copy of that standard, as well as a copy of a proposed amendment, are enclosed for your consideration.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3425OpenMr. Terry Coleman, Codes and Safety Manager, Airstream, Jackson Center, OH 45334; Mr. Terry Coleman Codes and Safety Manager Airstream Jackson Center OH 45334; Dear Mr. Coleman: This responds to your March 26, 1981, letter asking for a clarificatio of the certification requirements applicable to vehicles that you manufacture. The units frequently are completed by you, but in some instances, they are shipped to a final manufacturer for completion of the interior work.; Your first question asks whether you should label the vehicle as final-stage manufacturer since your vehicle is road worthy and needs only the addition of an interior finish prior to sale. In order to certify the vehicle as a final-stage manufacturer, the vehicle that you produce must be a completed vehicle (49 CFR Part 568). A completed vehicle is one that is finished and requires no further manufacturing operations to perform its intended functions with the exceptions of minor finishing operations or readily attachable components. If your vehicle is completed in a manner that it can perform its intended functions, you may label the vehicle as a final-stage manufacturer. The person performing alterations on your vehicle may then be required to add an alterer's label.; If the finishing operation that will be made to your vehicle is mor than the attachment of readily attachable components or minor finish work, the person doing the finishing work may label the vehicle as a final-stage manufacturer. In determining whether the installation of a bathroom, kitchen, furniture, beds, appliances, or seats is an installation of readily attachable components, you should consider whether it requires special expertise or tools. If it requires either, it is not the installation of readily attachable components.; Your second question asks whether your vehicle would be considered chassis-cab in those instances where another manufacturer might be attaching a final-stage label. The answer to this question is no. The definition of chassis-cab in part 567, *Certification*, states that it is a vehicle with a completed occupant compartment that needs only the addition of work performing or load carrying components to complete its function. It appears that your vehicle does not have a completed occupant compartment and, therefore, would not be considered a chassis-cab.; Finally, you ask what will happen if you label the vehicle as final-stage manufacturer and a subsequent manufacturer significantly alters the vehicle. You ask whether you could treat the vehicle as an incomplete vehicle and furnish the documentation required by Part 568. If you label the vehicle as a final-stage vehicle, you cannot treat it as an incomplete vehicle. However, you may convey information similar to that conveyed in an incomplete vehicle document to the subsequent manufacturer to ensure that it can comply with all of the standards. In fact, that manufacturer may require such information in order to be able to make the necessary modifications.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1418OpenMr. Gary T. Rath, General Manager, Mobile Auto Glass of Iowa, Inc., 1600 Second Avenue, Des Moines, IA 50314; Mr. Gary T. Rath General Manager Mobile Auto Glass of Iowa Inc. 1600 Second Avenue Des Moines IA 50314; Dear Mr. Rath: Thank you for your letter of January 30, 1974, concerning requirement for replacement glazing material in trucks and buses.; Glazing materials for use in motor vehicles must comply with th requirements of Federal Motor Vehicle Safety Standard No. 205, Glazing Materials, which incorporates the American National Standards Institute Standard No. Z26.1-1966. Section S6 of Standard No. 205 specifies requirements for certification and marking.; Paragraph S6.4 and S6.5 of Standard No. 205 covers the specifi question you asked. If you cut a section of glass to which this standard applies, for use in a motor vehicle or camper, you are required to mark that glass in accordance with section 6 of Standard No. Z26.1-1966 and to certify that it complies with the standard in accordance with section 114 of the National Traffic and Motor Vehicle Safety Act.; I am enclosing a copy of Standard No. 205, Standard No. Z26.1-1966 an section 114 of the National Traffic and Motor Vehicle Safety Act. If I can be of further assistance, do not hesitate to contact me.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl 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.