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
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ID: aiam3847OpenMr. C. I. Nielsen III, Vice President - Marketing, Wesbar Corporation, Box 577, West Bend, WI 53095; Mr. C. I. Nielsen III Vice President - Marketing Wesbar Corporation Box 577 West Bend WI 53095; Dear Mr. Nielsen: This is in reply to your letter of May 16, 1984, to Mr. Vinson of thi office seeking an interpretation of Motor Vehicle Safety Standard No. 108. You wish to know whether the minimum effective projected luminous lens area for stop lamps and turn signal lamps on trailers whose overall width is 80 inches or greater is 8 square inches or 12 square inches. You cite an apparent conflict between paragraph S4.1.1.6 and SAE Standard J586d, and paragraph S4.1.1.7 and SAE Standard J588f. You have asked for an interpretation so that Wesbar may properly design a 'combination tail lamp.'; First, we will confirm the advice provided by 'D.O.T. staff people that the latest SAE revisions, J586d and J588f, have not been adopted.; You do not state the intended use of your proposed lamp, so we wil assume that it will be sold to trailer manufacturers as original equipment, and to the aftermarket as replacement equipment. As original equipment, it must comply with the requirements specified in Table I of Standard No. 108, SAE J586c for stop lamps and SAE J588e for turn signal lamps. Paragraph 3.2 of each standard specifies a minimum effective projected luminous lens area of 8 square inches.; Paragraphs S4.1.1.6 and S4.1.1.7 become relevant, however, if Wesba intends the lamp as replacement equipment on trailers manufactured before September 1, 1978, and after January 1, 1972 (turn signal lamps) and January 1, 1973 (stop lamps). Under paragraphs S4.1.1.6 and S4.1.1.7, replacement stop and turn signal lamps for trailers manufactured within the 1972-1978 time frame may meet either J586b or J586c, and either J588d or J588e. We note that neither J586b nor paragraph S4.1.1.6 establish a minimum luminous lens area for stop lamps. However, a manufacturer who chooses to comply with paragraph S4.1.1.7 rather than J588e would have to provide the minimum specified luminous lens area of 12 square inches for turn signal lamps of trailers whose overall width was 80 inches or more, the requirement specified in J588d for Class A turn signal lamps. We view this interpretation as one of historical interest than (sic) current relevance.; In summary, if Wesbar designs its lamp to the 8-inch requirement, i would appear to meet specifications for application either as original or replacement equipment.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2755OpenMr. Harold A. Bullock, 1402 Redway Lane, Houston, Texas 77062; Mr. Harold A. Bullock 1402 Redway Lane Houston Texas 77062; Dear Mr. Bullock: This responds to your December 29, 1977, letter asking whether Standar No. 124, *Accelerator Control Systems*, applies to a cruise control device that you manufacture.; In Docket 69-20, Notice 3, to which you refer in your letter, th National Highway Traffic Safety Administration stated that Standard No. 124 contains no requirements for cruise controls. Therefore, the standard does not apply to them. There are no other safety standards applicable to these devices.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5090OpenMr. T. Kouchi Director & General Manager Automotive Equipment Development & Administration Dept. Stanley Electric Co. Ltd. 2-9-13, Nakameguro-ku, Meguro-ku Tokyo 153, Japan; Mr. T. Kouchi Director & General Manager Automotive Equipment Development & Administration Dept. Stanley Electric Co. Ltd. 2-9-13 Nakameguro-ku Meguro-ku Tokyo 153 Japan; "Dear Mr. Kouchi: This responds to your letter of October 8, 1992, wit respect to photometric test methods for a center high-mounted stop lamp using light emitting diodes (LEDs) as light sources. Your letter presents certain procedures and asks for associated revisions in Federal Motor Vehicle Safety Standard No. 108. After review, we have come to the conclusion that your method of proposed testing is allowable under Standard No. 108, but more stringent than what the standard requires. In the section of your letter called 'BACKGROUND', you state that you usually follow the technical guidance of SAE J1889 as a standard practice for LED lighting devices. There is no requirement in Standard No. 108 or in any of the SAE standards incorporated by reference in Standard No. 108 that requires you to follow the test methodology of J1889. Thus, when you say that you 'must always allow a margin of the same percentage when designing initial light output of the lamp, which necessitates increase in the number of LEDs used, lamp size, product cost, and, therefore, user's expense', you are placing a burden upon yourself that does exist under J1889, but one which is not necessary for designing for compliance with Standard No. 108. You have proposed a solution for the problem you have created by following J1889, and you provide three specific reasons in support. The third reason is based upon your interpretation of SAE J575's warpage test, under which you test operating cycles of 5 minutes on and 5 minutes off. However, you reference a version of J575 which does not apply to center high-mounted stop lamps. Paragraph S6.1 of Standard No. 108 specifies that J575e, August 1970, applies to high-mounted stop lamps designed to conform to SAE Recommended Practice J186a. SAE J575, August 1970, simply specifies that the device is to be operated in the test in the same manner as it will be operated in service, far different than the cycle method you employ. Thus, you have requested that we revise Standard No. 108 by adding a new provision that center high-mounted stop lamps shall be energized for a minimum of 5 minutes before measurement of photometric minima. We note that nothing prohibits you from testing in such a manner, but we believe that an amendment of this nature is not required because the present allowable method of testing does not call for it. You have asked for our comments on four steps of photometric measurement, and our permission to follow them. There is no reason you may not follow them, if you wish, but they are unnecessary to design for compliance under Standard No. 108. I hope that this is responsive to your questions. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam0768OpenMr. F. Michael Petler, Assistant Manager, Product Development Department, U.S. Suzuki Motor Corporation, 13767 Freeway Drive, Santa Fe Springs, California 90670; Mr. F. Michael Petler Assistant Manager Product Development Department U.S. Suzuki Motor Corporation 13767 Freeway Drive Santa Fe Springs California 90670; Dear Mr. Petler: This is in response to your letter of July 11, 1972, asking whethe Suzuki switches 577-2 and 577-5 comply with the headlamp beam operational requirements of Standard No. 123.; We assume that the letters 'L' and 'H' on each switch means 'low beam and 'high beam' respectively. Each switch has two positions, the upper on each marked 'L' and the lower marked 'H'. Standard No. 123, as you have noted, requires that a headlamp beam control switch provided an upper beam by pushing up, and a lower beam by pushing down. You have commented that 'in their current state of design these headlamp beam switch functions are the opposite as specified in Standard No. 123.'; Thus, as you appear to have surmised, switches 577-2 and 577-5 do no meet the headlamps beam operational requirements of Standard No. 123.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam1529OpenMr. Beller,Alfred Teves GMBH,6 Frankfurt/Main 2,Postfach 119155, Germany; Mr. Beller Alfred Teves GMBH 6 Frankfurt/Main 2 Postfach 119155 Germany; Dear Mr. Beller:#This responds to your May 10, 1974, request fo permission to stamp label information on hose assemblies in place of banding, and to reduce S9.2.5 burst pressure from 350 to 100 psi, and your further request for an interpretation of the status of an inline check valve as part of a vacuum brake hose.#The inline check valve is not subject to Standard No. 106, *Brake hose*, as a brake hose end fitting. In this configuration, the couplers depicted in your drawing are the clamps, and the check valve is a separate component to which the hose assemblies are attached.#The issue of stamping instead of banding will be answered in our upcoming Notice 11 in response to petitions for reconsideration of the brake hose standard.#Your petition for a reduction in the burst strength requirement for vacuum hoses is denied. The minimum burst pressure of 350 psi was established by the Society of Automotive Engineers in 1942, taking into consideration the effects of backfire pressure and the severe underhood environment to which vacuum hose may be exposed. Hoses with this burst pressure have provided excellent reliability and durability. We have no data to justify a reduction in burst strength in view of the two hazards just cited.#Sincerely,Robert L. Carter,Associate Administrator,Motor Vehicle Programs; |
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ID: aiam3514OpenWilliam D. Brusstar, Jr., Esq., General Motors Corporation, General Motors Building, 3044 West Grand Boulevard, Detroit, MI 48207; William D. Brusstar Jr. Esq. General Motors Corporation General Motors Building 3044 West Grand Boulevard Detroit MI 48207; Dear Mr. Brusstar: This is in response to your letter of December 16, 1981, requesting listing of those states whose certificates of title have been approved by the agency for use in lieu of the separate Federal odometer form.; The Odometer Disclosure Requirements (49 CFR Part 580) provide that th transferor of a vehicle may make the disclosure required by the Federal odometer laws on the state certificate of title, if the state title document contains essentially the same information required on the Federal odometer disclosure statement. If the information contained on the state certificate of title varies from that required by the Federal form, the state must obtain the approval of this agency before its certificate of title can be used as a substitute for the Federal form.; In order to spare states the burden of an apporval (sic) process th agency has indicated that certain variations from the Federal form are acceptable. In the *Federal Register* notice of August 1, 1977, which amended the disclosure regulation, we gave examples of shortened forms that would be acceptable. A state title can be considered to be approved for use as a full disclosure statement if it varies from the Federal form in only those aspects noted in the August 1, 1977, notice, a copy of which is enclosed.; The following states have odometer statements on their motor vehicl title forms that are consistent with the requirements of the Federal law:; >>>Maryland, Massachusetts, Michigan, Minnesota, Ohio, Pennsylvania Hawaii, New York, North Dakota<<<; In addition, the following states submitted title forms to the agenc asking for approval but had unacceptable statements. Each state was advised that before its form could be approved, certain additional information was required on its certificate of title. We do not know whether that information has been included on the titles.; >>>North Carolina, Delaware, South Dakota, South Carolina, Indiana Virginia, Washington, Utah, Wisconsin, New Mexico<<<; If you have any further questions, please do not hesitate to write. Sincerely, David W. Allen, Assistant Chief Counsel |
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ID: aiam1483OpenMr. Al Zajic, Project Engineer, American Trailers, Inc., 5702 E. Admiral Place, 15708 Admiral Station, Tulsa, OK 74115; Mr. Al Zajic Project Engineer American Trailers Inc. 5702 E. Admiral Place 15708 Admiral Station Tulsa OK 74115; Dear Mr. Zajic: This responds to your April 12, 1974, question whether a permanentl attached steerable axle on a trailer is required (1) to meet the S5.3.2 stopping distance requirement with no uncontrolled lockup of any wheel above 10 mi/h, and (2) to meet the parking brake requirements for trailer converter dollies or for all other vehicles.; The answer to your first question is yes. The steerable axle(s) of an trailer must meet the stopping distance requirements of S5.3.2 with no uncontrolled lockup of wheels above 10 mi/h.; In answer to your second question, the permanently attached steerabl axle you describe is not a separate vehicle which would qualify as a trailer converter dolly. Therefore the axle is simply part of a trailer which must meet the parking brake requirements of either S5.6.1 or S5.6.2. Neither of these options specifies that there be parking brakes on steerable axles, although in satisfaction of S5.6.2 (grade holding), the manufacturer could utilize parking brakes on the steerable axle.; Yours truly, Richard B. Dyson, Chief Counsel |
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ID: aiam4681OpenMs. Linda L. Conrad Nives Ford, Inc. 15690 South Harlem Avenue Orland Park, IL 60462; Ms. Linda L. Conrad Nives Ford Inc. 15690 South Harlem Avenue Orland Park IL 60462; "Dear Ms. Conrad: This responds to your letter asking what lega obligations are imposed on car dealers to replace air bags on used vehicles accepted as trade-ins. Your letter explained that your dealership has received, as a trade-in, a 1989 car that had a driver-side air bag as original equipment. According to your letter, the car had been in a crash and the air bag was deployed. Hence, when this car was taken in trade by your dealership, its air bag was not functional. You asked whether any law requires you to replace the deployed air bag with a new air bag before selling the car. In response to your question, we can advise you as follows: (1) Federal law does not require a car dealer to replace a deployed air bag in a used vehicle, (2) a dealer may be required by State law to replace that equipment, or be liable for failure to do so, and (3) our agency strongly encourages dealers to replace deployed air bags whenever vehicles are repaired or resold, to ensure that the vehicles will continue to provide maximum crash protection for occupants. We will first address the Federal legal issues, since our agency administers the Federal vehicle safety law. 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. NHTSA has exercised this authority to issue Standard No. 208, Occupant Crash Protection (49 CFR /571.208). Among other things, Standard No. 208 requires that cars be equipped with automatic crash protection. 'Automatic crash protection' means that a vehicle is equipped with occupant restraints that require no action by vehicle occupants. The performance of automatic crash protection is dynamically tested, that is, the automatic systems are required to comply with certain injury reduction criteria as measured by test dummies in a barrier crash test at speeds up to 30 mph. The requirement for automatic crash protection was phased-in for passenger cars, beginning with 1987 model year new cars. That phase-in is now completed, and all passenger cars manufactured on or after September 1, 1989 are required to be equipped with automatic crash protection. Section 108(a)(1)(A) of the Safety Act (15 U.S.C. 1397(a)(1)(A)) specifies that, 'No person shall manufacture for sale, sell, offer for sale, or introduce or deliver for introduction in interstate commerce, or import into the United States, any motor vehicle or item of motor vehicle equipment manufactured on or after the date any applicable Federal motor vehicle safety standard takes effect under this title unless it is in conformity with such standard ...' (Emphasis added) Because of this statutory requirement, your dealership cannot legally sell or offer for sale a new car equipped with an air bag if you know that the air bag has been deployed. However, section 108(b)(1) of the Safety Act (15 U.S.C. 1397(b)(1)) provides that the prohibitions in section 108(a)(1)(A) 'shall not apply to the sale, offer for sale, or the introduction or delivery for introduction in interstate commerce of any motor vehicle after the first purchase of it in good faith for purposes other than resale.' In other words, once the 1989 Chrysler LeBaron described in your letter was sold and delivered to its first retail purchaser, the vehicle was no longer required by Federal law to comply with Standard No. 208. After the first purchase of a vehicle in good faith for purposes other than resale, the only provision in Federal law that affects a vehicle's continuing compliance with an applicable safety standard is set forth in section 108(a)(2)(A) of the Safety Act (15 U.S.C. 1397(a)(2)(A)). 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, unless such manufacturer, distributor, dealer, or repair business reasonably believes that such vehicle ... will not be used (other than for testing or similar purposes in the course of maintenance or repair) during the time such device or element of design is rendered inoperative. In the case of passenger cars equipped with air bags pursuant to Standard No. 208, this section would prohibit any manufacturer, distributor, dealer, or repair business from removing, disabling, or otherwise 'rendering inoperative' the air bags, except as needed to make repairs to the car. When any such repairs are completed, the car must be returned to the customer with the air bag capable of functioning at least as well as it was able to do when the car was received by the manufacturer, distributor, dealer or repair business. Any violations of this 'render inoperative' prohibition in the Safety Act would subject the violator to a potential civil penalty of up to $1,000 for each violation. Please note that the 'render inoperative' provision does not impose an affirmative duty on dealers to replace equipment that was previously removed by someone else, or to repair equipment that was damaged in a crash. Thus, if your dealership purchases a used car that was originally equipped with an air bag pursuant to Standard No. 208, and the air bag was deployed before your dealership took possession of the car, Federal law does not require your dealership to replace the deployed air bag with a functioning air bag before you resell the car. Despite the absence of any requirement in Federal law, dealers may still be required by State law to replace deployed air bags, or they may be liable for failing to do so. You should be aware that the individual States have authority to require that used vehicles have certain equipment installed and functioning when the used vehicles are sold. You may wish to contact the State of Illinois to learn if there are any applicable laws or regulations that would apply in these circumstances. Additionally, you may wish to consult a private attorney familiar with the law in the State of Illinois regarding potential liability in tort for your dealership in these circumstances. While such issues are beyond this agency's area of legal expertise, we do note that every State provides for some degree of civil liability for consumer products and repair work. The potential for finding a car dealer liable may be greater when that dealer sells a used vehicle without one of the originally-installed safety systems intact and functional. As a final note, and in addition to the legal considerations, it is NHTSA's strong policy recommendation that dealers always replace air bags following deployment, unless the vehicle is to be junked. Indeed, we have long recommended the repair, restoration, or replacement of all safety systems that may have been damaged in a crash, including the safety belts and brakes, as well as the air bag systems now being installed in passenger cars. While air bags are in some respects 'supplemental' to safety belts, in that the air bags provide additional protection, the air bags are nevertheless vitally important to the vehicle's overall capability to protect occupants in a crash. Those vehicles are designed so that the air bag will always work, even if the safety belt is not worn, and the safety belt system is designed to work in conjunction with the air bag in serious frontal crashes. Additionally, the consumer information available to the purchaser of the used car described in your letter -- in the vehicle owner's manual, from the carmaker and insurance companies, and from NHTSA and other safety groups -- would identify the car as one equipped with a driver-side air bag. The purchaser may well expect a used car to provide the safety equipment that was provided by the original manufacturer. In short, from the standpoints of auto safety, dealer risk management, consumer protection, customer relations, and good business practices, NHTSA strongly advocates the replacment of deployed air bags. I hope this information is useful. If you have any further questions or need additional information on this subject, please feel free to contact Steve Kratzke of my staff at this address or by telephone at (202) 366-2992. Sincerely, Stephen P. Wood Acting Chief Counsel"; |
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ID: aiam1179OpenMr. R. J. Updegraff, Manager, Kysor of Cadillac, 1100 Wright Street, Cadillac, MI 49601; Mr. R. J. Updegraff Manager Kysor of Cadillac 1100 Wright Street Cadillac MI 49601; Dear Mr. Updegraff: This is in reply to your letter of June 22, 1973, concerning th applicability of section S5.1.4, *Pressure gauge*, of Standard No. 121, to an electronic gauge that displays the air pressure under normal conditions only when the driver pushes a switch but that provides continuous display at pressures below 70 p.s.i.; Section S5.1.4 requires a pressure gauge to be 'readily visible.' Use in this context, 'readily visible' means visible whenever the driver wants to see it. It does not mean that the air pressure level should be continuously visible. As we understand your system, the driver could determine the air pressure at any time by pushing the 'air pressure' button. We have concluded that this operation satisfies the intent of S5.1.4 and that your system would be permissable (sic) under that section.; The low pressure warning signal is required by section S5.1.5 and mus be separate from the pressure gauge. You state that you provide a flashing red light and an audible alarm, in addition to providing continuous readout of air pressure below 60 p.s.i. This would appear to conform to S5.1.5.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam3144OpenMr. H. J. T. Young, Vice President - Technical Affairs, SEV Corporation 33201 Harper Avenue, St. Clair Shores, MI 48082; Mr. H. J. T. Young Vice President - Technical Affairs SEV Corporation 33201 Harper Avenue St. Clair Shores MI 48082; Dear Mr. Young: This is in reply to your letter of September 24, 1979, to Mr. Vinson o this office in which you requested an interpretation S4.1.1.19 of Federal Motor Vehicle Safety Standard No. 108.; S4.1.1.19 states: >>>A lamp manufactured on or after January 1, 1974 and designed to us a type of bulb that has not been assigned a mean spherical candlepower rating by its manufacturer and is not listed in SAE Standard J573d 'Lamp Bulbs and Sealed Units', December 1968, shall meet the applicable requirements of this standard when used with any bulb of the type specified by the lamp manufacturer, operated at the bulb's design voltage. A lamp that contains a sealed-in bulb shall meet these requirements with the bulb operated at the bulb's design voltage.<<<; It is noted that this paragraph consists of two sentences. You hav asked whether the 'lamp' and 'bulb' of the second sentence are the same 'lamp and bulb' of the first sentence.; The answer is no. The first sentence would require testing, at th bulb's design voltage, of bulbs used in sealed beam headlamps but not of bulbs used in, for example, taillamps. The former, though listed in J573d (Table 2), is not assigned a mean spherical candlepower rating since these bulbs emit shaped beams while the latter is used in the sealed lamp, it is tested at the bulb's design voltage rather than using the rated mean spherical candlepower. Furthermore, the rulemaking history of the paragraph clearly indicates that the two requirements are separate. As the agency noted in the preamble to the proposal, 'The proposal specifies that when no rating has been assigned by the bulb manufacturer or the SAE *or* if the lamp is sealed and the bulb cannot be replaced, the bulb shall be operated at design voltage' (emphasis supplied) (38 FR 16230).; You noted that your question relates to the voltage required b Standard No. 108 for the photometric testing of a sealed beam headlamp that utilizes a European halogen bulb that meets ECE Regulation 37.; Since J579c requires the test voltage to be 12.8 volts for all th sealed beam bulbs, the photometric test should be at 12.8 volts and not at the so-called 'system voltage' of 12 volts.; I hope this is responsive to your request. |
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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.