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: aiam1129OpenHonorable Warren G. Magnuson, United States Senate, Washington, DC 20510; Honorable Warren G. Magnuson United States Senate Washington DC 20510; Dear Senator Magnuson: You wrote shortly after Mr. Toms' briefing on passive restrain technology to request my views on the implementation of Standard 208. The National Highway Traffic Safety Administration has taken a number of steps to lay the groundwork for sound decisions on this subject. I want to outline those steps for you and describe our policy regarding interim restraint systems.; As a result of the decision in *Chrysler* v. *Department o Transportation*, the principal focus of NHTSA has been on the test dummy used in Standard 208. Work has now progressed to the point of proposing a new test dummy specification, on which NHTSA is requesting comments. The court in *Chrysler* instructed NHTSA to delay the effective date for the implementation of passive restraints until a reasonable time after test dummy specifications are issued. Thus, NHTSA is obliged to consider the comments it receives on the dummy in forming its judgment as to when passive restraints should be required.; In order to enable a large scale passive restraint evaluation to b conducted, the agency has proposed to adopt the new dummy proposal as part of the optional passive restraint systems allowed after August 1973. This step will allow a manufacturer such as General Motors, which has plans for building up to 100,000 air bag equipped cars in model year 1974, to proceed with its plans.; During the period in which active and passive restraint options ar available to manufacturers, NHTSA will continue its efforts to increase seat belt usage. Standard 208 now requires seat belt interlock systems as the alternative to passive systems. In a decision announced on April 20, the agency rejected petitions from several manufacturers to delete the interlock system and reaffirmed its position that the interlock is an appropriate means of increasing belt usage.; The Department is making every effort to increase seat belt use, bot through the encouragement of mandatory usage laws and through the provision of devices such as the interlock. We expect that such measures will contribute to a reduction in the rate of death and injury on our highways.; Sincerely, Claude S. Brinegar |
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ID: aiam3114OpenMr. Ronald P. Mitchell, Executive Vice President, Phillips Motor Car Corporation, 1301 West Copan Road, Suite 3E, Pompano Beach, CA 33046; Mr. Ronald P. Mitchell Executive Vice President Phillips Motor Car Corporation 1301 West Copan Road Suite 3E Pompano Beach CA 33046; Dear Mr. Mitchell: This is in reply to your letter of September 22, 1979, asking whethe Phillips Motor Car Corporation is a 'manufacturer' or 'alterer' of the Berlina Coupe.; As you have described it, Phillips removes the body from a 198 Corvette, lengthens the frame and install (sic) newly manufactured body parts, retaining the interior safety features of the original vehicle.; It is clear from your description that Phillips alters previousl certified vehicles 'other than by the addition, substitution, or removal of readily attachable components such as mirrors or tires and rim assemblies ...' and is, therefore, subject to the certification requirements of Title 49, Code of Federal Regulations, Section 567.7. I enclose a copy of the regulation for your information and would be pleased to answer such further questions as you may have.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1083OpenMr. George H. Jones, Executive Secretary, Independent Tire Dealer, P.O. Box 2835A, Birmingham, Alabama 35212; Mr. George H. Jones Executive Secretary Independent Tire Dealer P.O. Box 2835A Birmingham Alabama 35212; Dear Mr. Jones: This is in reply to your letter of February 26, 1973, requesting ou view of your booklet on Standard No. 117. We have the following comments.; On page 2, under the heading, 'Does a Retread Have to Pass All Thes Tests', you refer to a lack of availability of test wheels. On page 3, under the heading, 'How Expensive Could Testing Get?', you quote figures of $250.00 to $400.00. As you know, the standard no longer includes the high speed and endurance Tests, and while there are other laboratory test involved in testing strength and bead unseating, neither includes the use of the laboratory test wheel. Consequently, insofar as your statements may take into account laboratory wheel tests, they should be modified.; On page 3, under the heading, 'What if One Certified Doesn't Comply?' you state, 'If the tire was not produced with due care then you will have both a recall and the probability of a penalty being assessed.' Notification of defects to first purchasers, however, is not contingent upon a showing of due care, and must be made even if a manufacturer used due care. Whether a manufacturer exercises due care is relevant only to whether he is in violation of the ACT, and to civil penalties, but not to defect notification (recall). The reason is that a retreader's exercise of due care doesn't change the fact that potentially unsafe tires will be used unless their owners are notified.; On page 4, under the Heading, 'Must You Submit Information On Defect and Failures?': Under section 113(d) of the National Traffic and Motor Vehicle Safety Act (as amended in 1970), each retreader must furnish NHTSA with a true and representative copy of all notices, bulletins, or other communications sent either to dealers or purchasers with regard to any defect in his tires. This requirements applies to all defects, and you should review it. It is incorrect to say that retreaders are not required to submit information regarding defects to NHTSA.; On page 4, under 'What Casing Controls are Required?', you indicat that no tire may be retreaded which has exposed ply cord. However, the standard allows ply cord to be exposed at a splice (S5.2.1(b)). While you make this point later, on page 5, the way in which you do so seems more to contradict than clarify your earlier statement. We suggest you indicate that ply cord may be exposed at a splice in the earlier paragraph as well. The same thing can be said for the next section on page 4, 'May Tires With Exposed Ply Cord be Retreaded?' This section is also completely silent on the exception for ply cord at a splice, and should also be modified.; On page 4, under the heading, 'What are Restrictions on Good Casings?' you omit certain requirements. Casings without a symbol DOT that are to be retreaded must only be of those size designations specified in the table at the end of the standard. These casings must also have permanently labeled on them the size, and number of plies or ply rating. Both of these information items and the symbol 'DOT' must also be permanently labeled on each DOT casing that is to be retreaded.; On page 5, under the heading, 'Should We Use Affixed Labels o Permanent Molding On Tire?', the minimum size for permanent labeling under S6.3.2 has been changed to 0.0078 inches. This change does not, however, affect affixed labels.; On page 6, under the heading, 'Is Any Provision Made For Sizin Difference in Retreads?', you state a retread may be 10% over new tire physical and dimension requirements. The 10% allowance for section width is to be calculated on the section width specified in the Tables of Standard No. 109, for the tire size designation. New tires are allowed to exceed this figure by 7%. Consequently, retreads can exceed the new tire requirements by only 3% (10% of the table figure). To say they can exceed the new tire requirement by 10% may mislead some persons into thinking they can exceed the value in the table by 17% which, of course, is not correct.; Apart from these points, your booklet appears to us to be essentiall correct. It should prove helpful to retreaders.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4281OpenMr. M.B. Mathieson, Director of Engineering, Thomas Built Buses, L.P., P. O. Box 2450, High Point, NC 27261; Mr. M.B. Mathieson Director of Engineering Thomas Built Buses L.P. P. O. Box 2450 High Point NC 27261; Dear Mr. Mathieson: This is in reply to your letters to Francis Armstrong, Robert Williams and Taylor Vinson, all of this agency. I regret the delay in this reply. In summary, Thomas wishes to mount a body of its construction to a 'General Motors chassis model; G31303, certified by G.M. to have a 10,000 1lbs. maximum GVWR .' Tw prototypes have been operating. In testing for compliance with the frontal impact requirements of Standard No. 301, the rate of fuel leakage from a pinched or broken fuel line greatly exceeded the amount permitted by the standard. The test conducted by Thomas used sandbags to simulate occupant loading, and the impact velocity was reported to be 30.4 m.p.h. You have asked the following four questions:; '1. Does the result of the frontal barrier crash test with th discovered fuel leak constitute a safety defect?'; '2. Does the result of the frontal barrier crash test with th discovered fuel leak constitute an apparent or alleged noncompliance with FMVSS 301 requirement?'; The result of the frontal barrier crash test do not constitute a alleged or apparent noncompliance with Standard No. 301 as the impact velocity exceeded the 30 m.p.h. maximum test requirement. In addition, the vehicle's test weight in your test exceeded the test weight specified in S7.1.6(b) of the standard. Further, those results do not constitute a safety related defect regardless of the use of the vehicle. For NHTSA to find a safety related defect at 30.4 m.p.h. would be the equivalent of imposing a new standard without following Administrative Procedure Act requirements for rulemaking.; However, in our view, Thomas could not in good faith certify complianc of the completed bus with the 30 m.p.h. requirements if there was a failure when a correctly loaded bus was tested at 30.4 m.p.h and no counterbalancing data showing passes in other tests. Had NHTSA conducted a test at 30.4 m.p.h. and found a failure, it would have proceeded to conduct another test in accordance with the specifications of Standard No. 301 and test at a speed slightly less than 30 m.p.h. and with a Part 572 dummy in the driver's seat.; >>>3. 'What is NHTSA's interpretation of the correct vehicle tes weight for FMVSS 301 certification testing of school buses and non school buses for vehicles in the under and up to 10,000 lbs.' class and equipped with seat belts required to comply with FMVSS 208?'<<<; The test weight is set forth in paragraph S7.1.6(b) of Standard No 301. That section provides that a 'bus with a GVWR of 10,000 pounds or less is loaded to its unloaded vehicle weight, plus the necessary test dummies as specified in S6., plus 300 pounds or its rated cargo load and luggage capacity weight, whichever is less,....'; >>>4. 'If Thomas Built Buses performs a certification test to th requirements of FMVSS 301 with a similar vehicle (equipped with required seat belts which are required to comply with FMVSS 208) at a test weight as noted by GM (approximately 7,500 pounds) and the results show full compliance, what is the legal status or implication of completing and offering for sale this type of vehicle at a GVWR of up to 10,000 lbs. and indicating that it complies with FMVSS 301 on the basis of a successful test at the lower GVWR.'<<<; This question cannot be answered because the facts stated in you question appear to be incorrect. Our review of the documentation you enclosed shows that GM has rated the incomplete vehicle at 10,000 pounds GVWR, rather than at approximately 7,500 pounds GVWR, as stated in your letter. GM has, however, specified the maximum unloaded vehicle weight as 6866 pounds, and stated that the completed vehicle will comply if its unloaded vehicle weight does not exceed this amount. It has also stated that the maximum unloaded vehicle weight plus 634 pounds (which, when added to 6866 pounds equals 7500 pounds) cannot exceed the vehicle's GVWR, which is 10,000 pounds in this case. GM therefore has made no weights outside those values, and the burden of certification falls upon the final state manufacturer who completers the vehicle in a manner outside the limits cited by GM.; I hope that this answers your questions. Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1579OpenMr. Tsukano, Sub-manager,Technical Division,Meiji Rubber & Chemical Co., LTD.,Kojima-Building, 10-2, Nishishinjuku, 1-Chome,Shin-juku, Tokyo, Japan; Mr. Tsukano Sub-manager Technical Division Meiji Rubber & Chemical Co. LTD. Kojima-Building 10-2 Nishishinjuku 1-Chome Shin-juku Tokyo Japan; Dear Mr. Tsukano:#This responds to your August 1, and July 30, 1974 request for approval of hydraulic and vacuum brake hose labeling. We have evaluated your examples based on the labeling requirements of the standard as amended by Notice 11 of Docket No. 1-5.#The hydraulic brake hose marking on 'Face A' appears to conform to the requirements of S5.2.2, assuming that letter 'size' refers to letter height. The interval between markings, represented by '--', also conform. 'Face B' is not regulated by our standard.#With regard to the markings for brake hose end fittings, the date (indicated by 'XY') is not required. If you choose to add the date to your markings, it should not interfere with the legibility of the required markings. I would like to point out that under Notice 11, the marking requirements do not apply to end fittings 'attached by deformation of the fitting about a hose crimping or swaging.' This means that hydraulic hose fittings for use in passenger cars need not be labeled.#The brake hose assembly markings you submit appear to conform to the requirements of the standard.#With regard to vacuum brake hose, your 'Face A' appears to conform to S5.2.2 if letter 'size' refers to letter height. S5.2.1 is not applicable and therefore the stripe is not required. 'Face B' is not regulated by our standard.#We have placed 'MRCC' on file as the manufacturer designation for your company. #Yours truly,Richard B. Dyson; |
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ID: aiam3544OpenMr. J. E. Bingham, Senior Test Engineer, British Standards Institution, Maylands Avenue, Hemel Hempstead, Herts HP2 4SQ, England; Mr. J. E. Bingham Senior Test Engineer British Standards Institution Maylands Avenue Hemel Hempstead Herts HP2 4SQ England; Dear Mr. Bingham: This responds to your letter of January 5, 1982, concerning Standar No. 209, *Seat Belt Assemblies*. You are correct that my letter of June 1, 1981, should have referred to S5.1(d) rather than S5.2(d). Likewise, I assume that where you have referred to sections 4.1(d), (e), and (f) in your letter, you mean sections 4.2(d), (e), and (f).; My letter of June 1, 1981, was not meant as a definitive statement o what specific action the agency intends to take on Standard No. 209, but rather to acknowledge that the standard's provision on abrasion needs modification. The notice of proposed rulemaking for this action will allow you and other interested parties to comment on what precise changes you think should be made to the standard. I am placing a copy of your letter with its current suggestions in the public docket.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2586OpenMr. John Watson, Krystal Glass Co., 224 St. Francis Drive, Boulder Creek, CA 95006; Mr. John Watson Krystal Glass Co. 224 St. Francis Drive Boulder Creek CA 95006; Dear Mr. Watson: This responds to your March 11, 1977, question whether the staine glass portholes manufactured by your company for use on van vehicles have to comply with Safety Standard No. 205, *Glazing Materials*. You contend that since the portholes are backed by complying safety glazing the intent of Standard No. 205 is met, even though the stained glass itself is not safety glazing.; The National Highway Traffic Safety Administration (NHTSA) cannot agre with your interpretation. Standard No. 205 specifies performance requirements for glazing material for use in specified locations in motor vehicles. All parts of your stained glass porthole windows must comply with the requirements of the standard. The safety glazing that backs your portholes could be damaged during a crash and the vehicle occupants could be exposed to the noncomplying stained glass. The NHTSA, therefore, disagrees with your conclusion that the intent of Standard No. 205 is met by the Krystal Glass porthole windows.; You should be aware that paragraph S6.2 of the standard requires prime glazing material manufacturer to certify each piece of glazing material that is designed as a component of any specific motor vehicle or camper pursuant to Section 114 of the National Traffic and Motor Vehicle Safety Act, as amended, (15 U.S.C. S 1381, *et*. *seq*.), and by marking the glazing with the 'DOT' symbol and a manufacturer's code mark. A prime glazing material manufacturer is defined as one who fabricates, laminates, or tempers the glazing material. A manufacturer's code mark is assigned by the NHTSA upon the written request of a manufacturer.; Enclosed is a copy of the ANS Z26 standard, as requested in you telephone conversation with Hugh Oates of this office.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5243OpenErika Z. Jones, Esq. Mayer, Brown & Platt 2000 Pennsylvania Avenue, N.W. Washington, D.C. 20006-1882; Erika Z. Jones Esq. Mayer Brown & Platt 2000 Pennsylvania Avenue N.W. Washington D.C. 20006-1882; Dear Ms. Jones: This responds to your request for an interpretation o Federal Motor Vehicle Safety Standard No. 213, Child restraint systems. S5.2.3.2(b) of Standard No. 213 specifies a minimum thickness for materials of a certain compression- deflection resistance. You ask whether more than one piece of material may be used to meet the thickness requirement. The answer is yes. S5.2.3.2(b) does not require the material to be of a single piece, and the final rule that incorporated the requirement into Standard No. 213 did not address the issue. 44 FR 72131, December 13, 1979. Accordingly, more than one piece of material may be used. I hope this information is helpful. If you have any further questions, please contact us. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam0041OpenMr. D. J. Schrum, Electrical Testing Laboratories, Inc., 2 East End Avenue, New York, NY 10021; Mr. D. J. Schrum Electrical Testing Laboratories Inc. 2 East End Avenue New York NY 10021; Dear Mr. Schrum: Thank you for your letters of July 30, and August 9, 1968, concernin the test of seat belt anchorages which are anchored to a seat.; On the question regarding the test method for applying the load specified in paragraph S3.1.1, Motor Vehicle Safety Standard No. 207, we would agree with your conclusion to apply the loads at the required different points and directions simultaneously.; On the question of whether bucket seats with seat belt anchorage attached may be tested separately, the applicable paragraph in SAE J787b is 5.2 rather than 5.1 as stated in your letter. There is no test method specified therein relative to this question and accordingly, test of the bucket seat with seat belt anchorages attached may be tested either separately or in sets.; Sincerely, H. M. Jacklin, Jr., Acting Director, Motor Vehicle Safet Performance Service; |
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ID: aiam5613OpenMr. Dennis G. Moore President Sierra Products, Inc. 1113 Greenville Road Livermore, CA 94550; Mr. Dennis G. Moore President Sierra Products Inc. 1113 Greenville Road Livermore CA 94550; Dear Mr. Moore: This responds to your letter of July 31, 1995, wit respect to lens area requirements of amber turn signal lenses. You believe that 'by reducing the minimal area of the Amber Turn Signal light lens from 12 square inches to approximately 8 square inches or 6 square inches the U.S. would have more practical rules for U.S. Exports at no expense to Safety. You ask that, 'If NHTSA's Legal Council feels this error should be corrected through the Petitioning Process, I ask that this writing be considered a `Petition for Change of FMVSS; "108 Request''. Standard No. 108 contains two relevant regulations, on applicable to vehicles whose overall width is less than 80 inches, and one to those whose overall width is 80 inches or more. Under paragraph S5.1.1.26(a), the functional lighted lens area of a single turn signal lamp of either red or amber on a vehicle whose overall width is less than 80 inches shall be not less than 50 square centimeters. This is approximately 8 square inches. Therefore, no rulemaking is required to implement your recommendation. The standard that applies to turn signal lamps on vehicles whose overall width is 80 inches or more is SAE Standard J1395 APR85, incorporated by reference in Standard No. 108. Under its paragraph 5.3.2, the functional lighted lens area of a single turn signal lamp shall be at least 75 square centimeters, or approximately 12 square inches. Therefore, rulemaking is required to implement your recommendation. We are transmitting your letter to our Office of Safety Performance Standards for consideration as a petition for rulemaking to change the minimum lens area requirement for turn signal lamps on large vehicles from 75 to 50 square centimeters. On September 4, 1995, I determined that your letter met our procedural requirements for a petition. Accordingly, the Office of Safety Performance Standards will inform you not later than January 1, 1996, whether your petition has been granted. If you have any questions, you may refer them to Taylor Vinson of this Office (202-366-5263). Sincerely, John Womack Acting Chief Counsel"; |
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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.