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: aiam3312OpenMichael M. Packard, Commissioner, Indiana Bureau of Motor Vehicles, State Office Building, Indianapolis, IN 46204; Michael M. Packard Commissioner Indiana Bureau of Motor Vehicles State Office Building Indianapolis IN 46204; Dear Mr. Packard: This is in response to your letter of May 28, 1980, in which yo requested approval to use Indiana's Certificate of Title as a substitute for the Federal Odometer disclosure form required by 49 CFR Part 580.; Because the Federal odometer requirements that became effective as o January 1, 1978, contain a good deal of wish to include odometer information on their titles to use a shortened form that was adopted by the American Association of Motor Vehicle Administrators (AAMVA). We consider the AAMVA form to include the minimum amount of information necessary for an adequate disclosure. In addition to the information included on the Certificate of Title which you submitted to our office, the following information is also required:; >>>(1) a reference to State or Federal law, (2) a statement that the odometer reading reflects the amount o mileage over 99,999 miles,; (3) a statement that the odometer mileage is not actual, (4) the signature of the buyer.<<< Without these four items the title cannot be used in lieu of a separat Federal form. If this information is included, the National Highway Traffic Safety Administration will approve the title for use in lieu of the Federal form.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam2850OpenMr. H. J. T. Young, Vice President - Technical Affairs, Cibie Corporation, 725 South Adams Road, Suite 209, Birmingham, MI 48011; Mr. H. J. T. Young Vice President - Technical Affairs Cibie Corporation 725 South Adams Road Suite 209 Birmingham MI 48011; Dear Mr. Young: This is in belated reply to your letter of December 15, 1977 requesting an interpretation of Federal Motor Vehicle Safety Standard No. 108, *Lamps, Reflective Devices and Associated Equipment*. Your request concerned the legality of installation on motor vehicles of remote manual or of automatic headlamp aiming equipment.; If a headlamp assembly meets the requirements of Standard No. 108 whe installed with or without auxiliary means of aiming, we consider the assembly to be in conformance. Your device does not appear to impair the effectiveness of the required lighting equipment within the prohibition of S4.1.3, and either device that you described would apparently provide an additional safeguard against glare when the rear of the vehicle is heavily loaded.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3742OpenMr. Karl-Heinz Ziwica, Manager, Safety & Emission Control Engineering, BMW of North America, Inc., Montvale, NJ 07645; Mr. Karl-Heinz Ziwica Manager Safety & Emission Control Engineering BMW of North America Inc. Montvale NJ 07645; Dear Mr. Ziwica: This responds to your letter requesting an interpretation of Standar No. 105, *Hydraulic Brake Systems*. Your request was in regard to a type of brake reservoir you are considering producing which would contain common fluid for the brake circuits and the brake hydraulic power assist unit. The issue raised by your letter was whether section S5.4.2 of the standard permits the common fluid to be counted as part of the minimum capacity required for the braking system. As discussed below, the answer to that question is no.; The first sentence of section S5.4.2 states: >>>Reservoirs, whether for master cylinders of other type systems shall have a total minimum capacity equivalent to the fluid displacement resulting when all the wheel cylinders or caliper pistons serviced by the reservoirs move from a new lining, fully retracted position (as adjusted initially to the manufacturer's recommended setting) to a fully worn, fully applied position, as determined in accordance with S7.18(c) of this standard.<<<; As noted by your letter, the agency has previously interpreted thi section with respect to a brake reservoir servicing both the braking system and the clutch. In an October 9, 1981, letter to Toyota, we explained:; >>>This section specifies the total minimum fluid capacity that vehicle's braking system reservoirs must have. That amount is determined by reference to the vehicle's braking system, i.e., by the fluid displacement which results when all the wheel cylinders or caliper pistons serviced by the reservoirs move from a new lining, fully retracted position to a fully worn, fully applied position. The purpose of this requirement is to assure that a vehicle's braking system reservoirs have adequate fluid capacity to service the brakes.; The agency interprets section S5.4.2 to require that the minimum flui capacity requirements be met by fluid which is solely available to the brakes. If fluid is available to both the brakes and the clutch, some of that fluid will be used by the clutch in normal service and thus be unavailable to the brakes. In the event of clutch failure, all of the common fluid may be used by the clutch. Therefore, while Standard No. 105 does not prohibit manufacturers from producing master cylinders with reservoirs that have some fluid available to both the braking system and the clutch, none of that common fluid may be counted toward meeting the minimum requirements of section S5.4.2.<<<; This same rationale applies to a reservoir which contains common flui for the brake circuits and brake hydraulic power assist unit. As indicated in our October 1981 letter, the minimum fluid capacity requirements were determined by reference to the vehicle's braking system for the purpose of assuring that a vehicle's braking system reservoirs have adequate fluid capacity to service the brakes, i.e., the wheel cylinders and pistons. More specifically, the requirement for minimum capacity equivalent to the fluid displacement resulting when all the wheel cylinders or caliper pistons serviced by the reservoirs move from a new lining, fully retracted position to a fully worn, fully applied position, was based upon maintaining a sufficient supply of fluid to enable a vehicle to stop even when there was complete brake lining wear-out in the service brakes. Put another way, the requirement assures an adequate supply of brake fluid over the lifetime of the brake linings, even if a driver fails to add fluid as part of routine maintenance.; This purpose would not be met if fluid available to both the brak circuits and brake hydraulic power assist unit was counted toward meeting the minimum fluid capacity requirements. Some of the common fluid would be used by the brake hydraulic power assist unit in normal service and thus be unavailable to the brake circuits. Moreover, in some instances of brake hydraulic power assist unit failure (e.g., a failure in the brake hydraulic power assist unit return line), all of the common fluid might be used by that unit.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4087OpenPaul A. Lester, Esq., Shapiro, Lester & Abramson, P.A., Roland/Continental Plaza, 3250 Mary Street, Miami, FL 33133; Paul A. Lester Esq. Shapiro Lester & Abramson P.A. Roland/Continental Plaza 3250 Mary Street Miami FL 33133; Dear Mr. Lester: This is in response to your request of January 14, 1986, for a rulin that the lessor/seller may issue an odometer disclosure statement to the lessee/buyer at the inception of the lease and not at the time of transfer.; Title IV of the Motor Vehicle Information and Cost Savings Act, 1 U.S.C. SS 1981-1991, directs the Secretary of Transportation to prescribe rules requiring any transferor to give a written disclosure of certain information to the transferee 'in connection with the transfer of ownership.' Transfer of ownership is defined in accordance with State law. Florida law specifies that issuance of the automobile title certificate and license constitutes presumptive ownership of a vehicle. Therefore, the written disclosure is required to be given when the title certificate and license are issued. While the National Highway Traffic Safety Administration has granted exemptions to the regulations promulgated pursuant to the Act, we cannot issue an exemption to any provisions of the Act itself.; In addition to the Federal requirements, the Florida motor vehicl title law states: 'No notary public shall notarize a title transfer until the *seller* properly indicates the odometer reading.' West F.S.A. S 319.22 (emphasis added). Therefore, in addition to your request being prohibited by Federal law, it may also be prohibited under State law.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam1285OpenWilliam C. Burns, Esq., Schultz, Evans and Burns, P.O. Box 1493, Lafayette Bank and Trust Builidng(sic), Lafayette, Indiana 47902; William C. Burns Esq. Schultz Evans and Burns P.O. Box 1493 Lafayette Bank and Trust Builidng(sic) Lafayette Indiana 47902; Dear Mr. Burns: This is in reply to your letter of September 28, 1973 to Secretar Brinegar, concerning outside rear view mirrors.; The existing standard (No. 111) on *Rearview Mirrors*, is found i Title 49, Code of Federal Regulations S 571.111. Paragraph S3.2 established requirements for outside mirrors. This standard applies to all passenger cars and multipurpose passenger vehicles manufactured since January 1, 1968, and establishes requirements for original equipment mirrors. It does not apply to mirrors manufactured for the aftermarket.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam2503OpenMr. Tokia Iinuma, Nissan Motor Co., Ltd., P.O. Box 1606, Englewood Cliffs, N.J. 07632; Mr. Tokia Iinuma Nissan Motor Co. Ltd. P.O. Box 1606 Englewood Cliffs N.J. 07632; Dear Mr. Iinuma: This responds to your January 6, 1977, question regarding the effectiv date of the recent amendment to Standard No. 116, *Motor Vehicle Brake Fluids*, That specifies color coding requirements for brake fluids (41 FR 54942, December 16, 1976). You asked whether motor vehicles manufactured after the effective date for the color coding requirements (September 1, 1978) may be equipped with brake fluids manufactured prior to that date that do not conform to the color coding requirements. The answer to your question is yes. Paragraph S5.3 of Standard No. 116 specifies that motor vehicles having hydraulic brake systems shall be equipped with brake fluid that has been manufactured and packaged in conformity with the requirements of the standard. The agency interprets this to mean that vehicles shall be equipped with any brake fluid that conformed to the requirements of Standard No. 116 at the time the brake fluid was manufactured.; Sincerely, Frank Berndt, Acting Chief Counsel |
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ID: aiam4984OpenMr. Mark A. Sedlack Product Design Manager Century Products Co. 9600 Valley View Road Macedonia, OH 44056; Mr. Mark A. Sedlack Product Design Manager Century Products Co. 9600 Valley View Road Macedonia OH 44056; "Dear Mr. Sedlack: This responds to your letter seeking a interpretation of Standard No. 213, Child Restraint Systems (49 CFR 571.213). More specifically, you asked how compliance testing would be conducted for a rear-facing child restraint labeled for use by children weighing up to 25 pounds. The initial question we must address is what size test dummy would be used for compliance testing. S7.1 of Standard No. 213 provides that the six-month-old dummy is used for testing a child restraint system that is recommended by its manufacturer for use by children in a weight range that includes children weighing not more than 20 pounds. S7.2 of Standard No. 213 provides that the three-year-old dummy is used for testing a child restraint system that is recommended by its manufacturer for use by children in a weight range that includes children weighing more than 20 pounds. Since the rear-facing child restraint in your example is recommended for use both by children weighing less than and more than 20 pounds, either the six-month-old or the three- year-old dummy could be used in the agency's compliance testing, as provided in S6.1.2.3 of the standard. Your letter stated that you understood that this rear-facing child restraint would be subject to testing using the three- year-old dummy. However, you indicated that neither your company nor a testing facility understood how the three-year- old dummy could be installed in a rear-facing child restraint. You asked for clarification of how the three- year-old dummy could be installed. At the outset, I must note that it is impossible for me to offer any guidance for how to install the test dummy in your particular rear-facing child restraint because I do not know the details of your design. I can offer general guidance that you should be able to apply to your particular design. The procedures to be followed in positioning the three-year- old dummy in any child restraint other than a car bed are set forth in S6.1.2.3.1 of Standard No. 213. If the rear-facing child restraint does not physically permit the three-year-old dummy to be positioned in accordance with S6.1.2.3.1, then that rear-facing child restraint cannot be recommended by its manufacturer for use in the rear-facing position by children weighing more than 20 pounds. This conclusion is similar to the agency conclusion announced in a July 8, 1988 letter to Mr. Donald Friedman that an infant restraint so small it cannot accommodate the six-month-old test dummy cannot be certified as complying with Standard No. 213. In our letter to Mr. Friedman, the agency indicated that rulemaking could be initiated to sanction the use of an additional test dummy to evaluate the performance of a child restraint. However, that rulemaking would have to include an agency determination that this additional test dummy is a reliable surrogate for measuring the system's performance in an actual crash. We can make the same statements with regard to the situation described in your letter. You stated in your letter that you have tested your company's existing convertible seats in the rear-facing position 'with a CAMI dummy modified to 25 pounds with satisfactory results.' If you have any information or test data showing that the CAMI dummy so modified is a reliable surrogate for measuring the performance of your convertible systems in the rear-facing position, such information might be helpful to this agency in deciding whether to initiate rulemaking in this area. Until such a rulemaking action were completed and amended provisions in effect, however, you cannot recommend that a child restraint be used for children weighing more than 20 pounds if that child restraint cannot accommodate the three- year-old test dummy. I hope this information is helpful. If you have any further questions or need some additional information on this subject, please feel free to contact Deirdre Fujita of my staff at this address or by telephone at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel"; |
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ID: aiam2153OpenMr. Tokio Iinuma, Staff, Safety, Nissan Motor Co., Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Tokio Iinuma Staff Safety Nissan Motor Co. Ltd. 560 Sylvan Avenue Englewood Cliffs NJ 07632; Dear Mr. Iinuma: This is in response to your November 20, 1975, letter concerning th use of replacement parts which may affect a vehicle's compliance with a Federal motor vehicle safety standard that is applicable only to vehicles.; You have presented the example of a vehicle that, if equipped with door that does not have guard bars, would not be in compliance with Federal Motor Vehicle Safety Standard No. 214. Because that standard is applicable only to passenger cars, there is no prohibition on the mere *sale* of such doors for use as replacement equipment. However, Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act of 1966, as amended ('the Act'), specifies that; >>>No manufacturer, distributor, dealer, or motor vehicle repai business shall knowingly render inoperative, in whole or part, any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard, unless such manufacturer, distributor, dealer, or repair business reasonably believes that such vehicle or item of equipment 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. For purposes of this paragraph, the term 'motor vehicle repair business' means any person who holds himself out to the public as in the business of repairing motor vehicles or motor vehicle equipment for compensation.<<<; Therefore, the *installation* of a door that does not have guard bar is a violation of the Act, if that installation is performed by a manufacturer, distributor, dealer, or motor vehicle repair business. Installation of such a door by one of your dealers, for example, is not permitted.; Your letter also asked whether the use of such doors would be permitte in the future, in the event that Standard No. 214 is relaxed in a way that would permit the use of such doors on a new vehicle. It is the opinion of this agency that replacement of a door, or any other safety system installed in compliance with a Federal motor vehicle safety standard, with a system mandated by a later safety standard (even if the later standard imposes a less stringent level of performance) would not violate Section 108(a)(2)(A) of the Act, as amended.; Sincerely, Frank A. Berndt, Acting Chief Counsel |
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ID: aiam0494OpenDr. J. G. Lundholm, Jr., 8106 Post Oak Road, Rockville, MD 20854; Dr. J. G. Lundholm Jr. 8106 Post Oak Road Rockville MD 20854; Dear Dr. Lundholm: Thank you for your letter of November 2, 1971, to Secretary Volpe, i reference to our occupant crash protection program.; I am enclosing a copy of the proposed amendment to Federal Moto Vehicle Safety Standard No. 208, Occupant Crash Protection, which would allow an ignition interlock system as an option to front seat passive systems from August 15, 1973, to August 15, 1975. I am also enclosing an explanatory press release.; In regard to your question number one, we require that the interloc system be sequentially linked to the seat switch, such that a person would have to fasten the belt, after being seated, each time he attempted to start the car.; With regard to your questions numbers two and three, the Nationa Traffic and Motor Vehicle Safety Act of 1966 permits us to establish standards which serve as guides for individual state safety programs. It is possible for the states to undertake such anti-tampering regulations. We will certainly be considering such actions once we determine the magnitude and effect of tampering in vehicles which have been produced to meet the Federal standards.; In regard to your question number four, I am not presently aware of an plans by insurance companies to require seat/shoulder belt usage in order to be reimbursed for collision coverage in case of an accident.; You are certainly correct in that the present shoulder belt design often make it difficult to have a properly adjusted shoulder belt and still be able to have a reasonable degree of freedom of movement during normal vehicle operation. We are attacking this problem on two fronts. Federal Motor Vehicle Safety Standard No. 101, Control Location, Identification and Illumination--Passenger Cars, requires that most critical controls, such as the steering wheel, headlamp switch, etc., be within reach by a person restrained by a lap and shoulder belt system. The present version of this standard does not include the parking brake or its release mechanism. The second action, which we are taking, is to propose a requirement that shoulder belt systems in cars manufactured after August 15, 1973, shall be equipped with inertia reel retractors that allow freedom of movement except in a crash situation.; I appreciate your thoughtful comments and your intense interest in ou motor vehicle safety programs. It is very helpful to our efforts to improve highway safety when concerned citizens, such as yourself, take the time to bring their comments and suggestions to our attention.; Sincerely, Robert L. Carter, Acting Associate Administrator, Moto Vehicle Programs; |
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ID: aiam0181OpenMr. Warren M. Heath, Commander, Engineering Section, Department of California Highway Patrol, P. O. Box 898, Sacramento, CA 95804; Mr. Warren M. Heath Commander Engineering Section Department of California Highway Patrol P. O. Box 898 Sacramento CA 95804; Dear Mr. Heath: Thank you for your letter of September 10, 1969, concerning lamp bulb to be used in photometric tests.; In answer to your first question, photometric testing of lamps usin 1034 and 1157 bulbs should be conducted with the minor filament operating at four mean spherical candlepower to determine conformance to SAE J573b. Bulbs utilizing three candlepower minor filaments would not be in conformance with SAE J573b, however, as provided by the enclosed interpretation issued August 12, 1968, on bulbs and bulb sockets, such bulbs may be used in lamp assemblies conforming to Federal Motor Vehicle Safety Standard No. 108. In accordance with the interpretation, such bulbs should be treated as special bulbs and should be tested at the three candlepower rating.; In answer to your second question, if photometric tests are conducte with a bulb operated at either three or four mean spherical candlepower ratings, it is not acceptable to interpolate (or extrapolate) the data to determine acceptability of the lamp in the other bulb rating.; Sincerely, Robert Brenner, Acting Director |
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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.