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: aiam4413OpenD. F. Landers, PSI Mobile Products Inc., 25 Eldredge, P.O. Box 1183, Mt. Clemens, MI 48043; D. F. Landers PSI Mobile Products Inc. 25 Eldredge P.O. Box 1183 Mt. Clemens MI 48043; Dear Mr. Landers: This is in response to your letter requesting confirmation of a Jul 11, 1983 determination by this agency that your special tow tractor vehicle is exempt from Federal motor vehicle safety standards. You indicate in your letter that you now have three sizes of tow tractors and that your market may expand to include commercial airline use as well as the Department of Defense.; Based on the information you have provided us, we confirm our previou determinations that baggage tow tractors are not subject to the Federal motor vehicle safety standards. The agency has consistently interpreted the definition of motor vehicle as excluding vehicles such as airport runway vehicles that are intended and sold solely for off-road use and are not equipped for highway use. Further, we note that section 571.7(c) of Title 49, Code of Federal Regulations, provides that; >>>No standard applies to a vehicle or item of equipment manufacture for, and sold directly to, the Armed Forces of the United States in conformity with contractual specifications.<<<; Your vehicles might become subject to the Federal motor vehicle safet standards if there is a material change in the facts regarding the intended or actual use, design or sale of your vehicles. Please remember that compliance with all Federal motor vehicle safety standards is the obligation of each manufacturer of motor vehicles or motor vehicle equipment. We appreciate your continuing efforts at classifying correctly your vehicles.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam0903OpenMr. Bob Bryan, Sales Coordinator - Direct Sales, Mobile Aerial Towers, Inc., 2314 Bowser Avenue, Fort Wayne, IN 46803; Mr. Bob Bryan Sales Coordinator - Direct Sales Mobile Aerial Towers Inc. 2314 Bowser Avenue Fort Wayne IN 46803; Dear Mr. Bryan: This is in reply to the questions you asked in your letter of Octobe 24, 1972, to Mr. Wells of the Federal Highway Administration concerning compliance with Standard No. 108 of trucks to which mobile aerial towers are mounted.; '1. The aerial tower is considered a load rather than part of th vehicle to be included in determining the overall length. Correct?'; Correct. '2. Are amber *intermediate side marker* lights and/or reflector required on the body?'; If overall length of the vehicle is 30 feet or more, intermediate sid marker lamps and reflectors are required, and they must be located at or near the midpoint between the front and rear side marker lamps and reflectors.; '3. Are amber *side marker* lights and/or reflectors required on th body?'; Front amber side marker lamps and reflectors are required to be mounte as far to the front as practicable on a vehicle. Generally, this is somewhere on the front fender, though in some configurations a manufacturer might determine that a location on the truck body is as far to the front as practicable.; '4. Are amber *clearance* lights and/or reflectors required on th *front* of the body?'; Yes. Front clearance lamps are required to indicate the overall widt of the vehicle and to be mounted 'as close to the top [of the vehicle, exclusive of load] as practicable.'; '5. If a unit is over 30 ft. long, will amber *side marker* lights an reflectors suffice *also* as amber *intermediate side marker lights and reflectors*?'; No, they will not. As the above answers indicate, the locatio requirements are different for front and intermediate side markers.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1611OpenMr. Tatsuo Kato, Staff, Safety, Nissan Motor Company, Ltd., 560 Sylvan Avenue, Englewood Cliffs, New Jersey 07632; Mr. Tatsuo Kato Staff Safety Nissan Motor Company Ltd. 560 Sylvan Avenue Englewood Cliffs New Jersey 07632; Dear Mr. Kato: This is in reply to your letter of September 11, 1974 asking for a interpretation of paragraph S5.3.5 of Standard No. 105-75. You indicate that a prospective Nissan design uses a common indicator lamp to show both loss if fluid pressure and low brake fluid level. You ask if the indicator lamp lens may be labeled 'Brake Failure.'; The answer is no. If separate indicator lamps are used, Standard No 105-75 allows words in addition to 'Brake' to indicate the specific area where a problem may exist, *e.g.* an indicator lamp may be labelled 'Brake Fluid' to indicate a low level of fluid. However, if a lamp indicates more than one type of condition, paragraph S5.3.5 specifies that only a single word, 'Brake', may be used. This alerts a driver in a general way that a problem exists somewhere in the brake system. We think the restriction of S5.3.5 preferable for most circumstances. In the configuration you propose for example, the word 'Failure' would not accurately describe a low level of brake fluid.; We appreciate your continued interest in vehicle safety. Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam2894OpenMr. D.P. Weiher, Office of Corporate Safety, Emissions and Noise Control, AM General Corporation, 32500 Van Born Road, Wayne, Michigan 48184; Mr. D.P. Weiher Office of Corporate Safety Emissions and Noise Control AM General Corporation 32500 Van Born Road Wayne Michigan 48184; Dear Mr. Weiher: This responds to your August 2, 1978, letter asking whether it i permissible to perform the tests of Standard No. 124, *Accelerator Control Systems*, with only part of the vehicle mechanism at the designated temperatures. You state further that there is not sufficient time to find an environmental chamber large enough to accommodate the size vehicle that you are testing.; "The National Highway Traffic Safety Administration (NHTSA) does no issue approvals of manufacturer's plans for compliance with agency standards. Standard No. 124 mandates that a vehicle shall meet the j requirements of the standard at any temperature between -40 degrees F. and 125 degrees F. When the agency tests for compliance with the standard, it fins a chamber sufficiently large to accommodate the entire vehicle and tests according to the standard. Any manufacturer deviation from this accepted test procedure carries with it certain risks that a vehicle may not conform to the requirements."; With respect to the vehicles that you are constructing, you state i your letter that they are being manufactured for use by the army. As such, These vehicles are not required to comply with the agency's safety standards, and the NHTSA would not test these vehicles for compliance.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3786OpenMr. Richard McCarl, American Isuzu Motors Inc., Whittier, CA 90601; Mr. Richard McCarl American Isuzu Motors Inc. Whittier CA 90601; Dear Mr. McCarl: This responds to your November 23, 1983 letter regarding th applicability of motor vehicle certification requirements to a new vehicle to be imported by Isuzu Motors. This small utility vehicle would be certified as a truck. Isuzu dealers will offer for the vehicle an optional rear seat which can be installed by simply bolting it to the vehicle. The basic vehicle already has the necessary mountings for the seat, so the seat installation can apparently be readily accomplished. You have asked whether installation of these seats constitutes 'alteration' of the vehicle by the dealer, requiring the addition of an alterer's label in accordance with 49 CFR 567.7.; Based on your description of the seat installation process, it appear that dealers installing the seats would be subject to 49 CFR 567.6, 'Requirements for persons who do not alter certified vehicles or do so with readily attachable components.' Since the seats appear to be 'readily attachable components,' section 567.6 requires dealers to leave the manufacturer's certification label in place and requires no alterer's label to be added.; If you have further questions on this matter, please contact us. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4043OpenMr. Roger F. Hagie, Government Relations Manager, Kawasaki Motors Corporation, U.S.A., P. O. Box 11447, Santa Ana, CA 92711; Mr. Roger F. Hagie Government Relations Manager Kawasaki Motors Corporation U.S.A. P. O. Box 11447 Santa Ana CA 92711; Dear Mr. Hagie: This responds to your April 11, 1986, letter to this office requestin an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 106, *Brake Hoses*. We regret the delay in our response; You asked whether brake hoses that comply with all requirements o Standard No. 106 except the whip resistance test of S5.3.3 may be used in locations not subject to movement during vehicle operation. As explained below, the answer to your question is no.; As you know, Standard No. 106 defines 'brake hose' as 'a flexibl conduit, other than a vacuum tubing connector, manufactured for use in a brake system to transmit or contain the fluid pressure or vacuum used to apply force to a vehicle's brakes.' Manufacturers of brake hoses must certify that their hoses comply with all applicable requirements of the standard. From your letter, it appears that while you agree that the equipment you manufacture are brake hoses, you believe that they should not be subject to whip resistance test because your hoses would not be used between articulating parts.; We do not agree that the whip test does not apply to brake hoses use between non- articulating parts. No provision has been made in the standard or in the whip resistance test of S5.3.3 to exclude hoses manufactured for use between non-moving parts. In contrast, the standard has set separate requirements under certain tests for brake hoses used between articulating parts when it is appropriate to distinguish between articulating and non-articulating applications (see, for example, the tensile strength test of S7.3.10 for air brake hose assemblies).; Further, we believe that there is a safety need to test brake hose intended for non-articulating applications for fatigue resistance, since they are also subject to vibration, bending and articulating stress while the motor vehicle is being operated or repaired.; If you have further questions, please let me know. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1241OpenMr. David E. Martin, Manager, Automotive Safety Engineering, Environmental Activities Staff, General Motors Technical Center, General Motors Corporation, Warren, MI 48090; Mr. David E. Martin Manager Automotive Safety Engineering Environmental Activities Staff General Motors Technical Center General Motors Corporation Warren MI 48090; Dear Mr. Martin: Dr. Gregory has asked me to reply to your letter of August 28, 1973, i which you request our endorsement of new labels General Motors intends to use to fulfill its responsibilities under part 567 of Title 49 of the Code of Federal Regulations.; The wording on the label meets the requirements of paragraph 567.4(g) The color of the paint under the label 'window' would determine conformity with the contrasting color requirements in paragraph 567.4(f).; It would appear that the material would '. . .be permanently affixed. .' if it '. . .is tightly bonded to the surface of the vehicle panel. . . .' However, it has not been the practice of the National Highway Traffic Safety Administration to endorse label materials.; Thank you for your continuing cooperation. Sincerely, Robert L. Carter |
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ID: aiam0846OpenMr. R. A. C. Dandy, Senior Engineer, Head of Mechanical Section, British Standards Institution, Hemel Hempstead Centre, Maylands Avenue, Hemel Hempstead, Herts, England; Mr. R. A. C. Dandy Senior Engineer Head of Mechanical Section British Standards Institution Hemel Hempstead Centre Maylands Avenue Hemel Hempstead Herts England; Dear Mr. Dandy: This is in further reply to your letter of July 26, 1972, concernin the seat belt retractor test procedures of section S5.2(k) of Motor Vehicle Safety Standard No. 209.; In our initial reply of August 21, we stated that the belt was to b retracted completely during the cycling, even though some vehicle installations might prevent complete retraction. After further examining the consequences of this position, we have concluded that it is in error.; The intent of the cycling sequence is to reflect the normal use of th belt over time. If the belt is designed to be installed in a vehicle in such a manner that during normal cycling a part of the webbing cannot be wound onto the retractor, a compliance test should employ the same restrictions of movement. We therefore conclude that you are correct in considering a belt to be fully retracted for purposes of Standard No. 209 when it is retracted as fully as the geometry of its installation permits.; Sincerely, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1754OpenMr. William J. Flanagan, Executive Director, New Jersey Turnpike Authority, New Brunswick, NJ 08903; Mr. William J. Flanagan Executive Director New Jersey Turnpike Authority New Brunswick NJ 08903; Dear Mr. Flanagan: This is in reply to your letter of December 3, 1974, requesting ou view whether the removal of portions of a tie bar in a truck tire, for the purpose of reducing tire noise, is subject to NHTSA's *Regrooved Tire* regulation (49 CFR Part 569). You state that the removal of the tie bar material does not require that the tread be cut to a depth equal to or deeper than the original groove depth.; We concur in your opinion that the partial removal of tire tie ba material is not subject to the *Regrooved Tire* regulations. This practice would not be considered the making of a 'regrooved tire' (49 CFR S 569.3(d)) as long as the removal of tie bar material did not extend to the original tread depth. Any removal or renewal of tread that did extend to at least the original tread depth, however, would be considered the making of a 'regrooved tire' and would be subject to the requirements set forth in S 569.7 of the regulation.; We are concerned, however, that this opinion may result in th indiscriminate removal of tire tie bar material from truck tires having varying tread designs. We believe it possible, notwithstanding the absence of regulations prohibiting such removal, that the removal of tie bar material could in some cases induce tread cracking, instability, and otherwise reduce the safe performance of truck tires. Consequently, we believe you should determine, through testing if necessary, that removal of tire tie bar material will not produce adverse results in tire performance before any large-scale project involving venting is implemented. Any such program should also take into account that effects of venting may differ among various tread designs. Finally, tread venting on new tires manufactured after March 1, 1975, could affect the conformity of those tires to Federal Motor Vehicle Safety Standard No. 119.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam3769OpenGreg Kreshel, P.E., V.P. Production, Alloy Trailers, Inc., P.O. Box 19208, Spokane, WA 99219; Greg Kreshel P.E. V.P. Production Alloy Trailers Inc. P.O. Box 19208 Spokane WA 99219; Dear Mr. Kreshel: This is in reply to your letter of October 25, 1983, to Mr. Vinson o my staff, in which you question the practice by Fruehauf of replacing upper rear identification lamps with reflectors, on certain trailers. You asked if it were possible that the manufacturer would say that the header was too narrow for a light to fit.; I enclose a copy of an interpretation this office furnished Fruehau and the State of Wisconsin on June 18, 1981, which will clarify this issue. In summary, Fruehauf demonstrated to us the impracticability of mounting the identification lamps at the top of a vehicle of this configuration (principally because of the vulnerability of the wiring). At the time, Fruehauf expressed its concern about conspicuity of its vehicles and assured us that it would investigate ways to improve it in future production. Apparently it decided that adding reflectors at the top, at the body edges and towards the middle where the doors open, was the most satisfactory way to enhance conspicuity, given the design of the vehicle.; Thank you for your interest in this question. 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.