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: aiam3404OpenMr. John S. Miskowicz, Gateway Industries, Inc., 17512 Carriage Way Drive, Hazel Crest, IL 60429; Mr. John S. Miskowicz Gateway Industries Inc. 17512 Carriage Way Drive Hazel Crest IL 60429; Dear Mr. Miskowicz: This responds to your letter of March 2, 1981, to Vladislav Radovic concerning Standard No. 213, *Child Restraint Systems*. Your letter was forwarded to this office for reply.; You asked whether a child restraint belt buckle must meet the buckl force release requirements when tested in an unloaded condition. In addition, you asked whether section 4.3(a) and 4.3(b) of Standard No. 209, *Seat Belt Assemblies*, are the only requirements of that standard which apply to buckles in child restraint systems. The answer is yes.; Section 5.4.3.5 of Standard No. 213 provides that each child restrain belt buckle, when tested in accordance with S6.2, must not release when a force of not more than 12 pounds is applied before the dynamic sled specified in S6.1 is conducted. The buckle must release when a force of 20 pounds is applied after the dynamic sled test. Section 6.2 provides that in conducting the belt buckle release force test, the appropriate test dummy is placed in the restraint and either a pull force of 20 pounds is applied, in the case of 6-month-old test dummy, or a 45 pound pull force is applied, in the case of the three-year-old test dummy. Thus, the buckle is not tested in an unloaded state.; Section 5.4.2 of the standard provides that each belt buckle has t conform to the 'requirements of S4.3(a) and S4.3(b) of FMVSS No. 209.' No other provisions of Standard No. 209 apply to belt buckles used in child restraints.; If you have any further questions, please let me know. Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam1439OpenMr. W. G. Milby, Project Engineer, Blue Bird Body Company, P.O. Box 937, Fort Valley, GA 31030; Mr. W. G. Milby Project Engineer Blue Bird Body Company P.O. Box 937 Fort Valley GA 31030; Dear Mr. Milby: This is in reply to your letter dated December 6, 1973, requestin clarification of the definition of school bus' as it appears in NHTSA regulations. You point out that school bus is defined for purposes of the Motor Vehicle Safety Standards in 49 CFR 571.3 to mean a bus designed primarily to carry children to and from school. . .', but is defined differently in Highway Safety Standard No. 17 (23 CFR 204.4), i.e., any motor vehicle with motive power, except a trailer, *used* to carry more than 16 pupils to and from school'. You also refer to our interpretation regarding Federal Motor Vehicle Safety Standard No. 217 which states that the term school bus' as defined in 49 CFR S 571.3 includes buses designed as school buses but which are not intended or sold to transport children to and from school. You state that as a result it is unclear whether buses designed but not used as school buses, including church and civic group buses, must be equipped with warning lamps under S4.1.4 of Motor Vehicle Safety Standard No. 108. In this regard, you state that you require purchasers to indicate on their purchase order whether the bus will be used primarily to transport children to and from school, and ask whether this is an acceptable form for a manufacturer to use to determine whether a vehicle will be used as a school bus.; We do not interpret Standard No. 108 to require warning lights on buse that are not intended to be used to transport school children. Our interpretation regarding Standard No. 217, exempting school bus-type buses from the emergency exit requirements of that standard (which applies as well to buses manufactured by Blue Bird), was based on what we believed at that time was a special need to exempt such buses from the requirements of that standard. We are aware of the inconsistency in the application of the definition of school bus' in Standards Nos. 108 and 217 and we intend to modify these requirements so that they will be applied consistently.; The difference between the definition ofBschool (sic) bus in th Highway Safety Act and in the Motor Vehicle Safety Standards under the Vehicle Safety Act is that the latter statute and the requirements issued thereunder apply to the manufacturing process. The requirements issued under the Highway Safety Act apply more directly to school bus use.; Whether a particular bus is a school bus cannot be ascertained merel by the representation of the purchaser. The manufacturer should base his decision as well on the objective characteristics of the vehicle, so that he can be reasonably certain that the purchaser's representations are *bona fide*.; Sincerely, Lawrence R. Schneider, Chief Counsel |
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ID: aiam0382OpenMr. Charles J. Calvin, Managing Director, Truck Trailer Manufacturers Association, 1413 K Street, N. W., Washington, DC, 20005; Mr. Charles J. Calvin Managing Director Truck Trailer Manufacturers Association 1413 K Street N. W. Washington DC 20005; Dear Mr. Calvin: This is in response to your letter of June 30, 1971, to Mr. Douglas W Toms, Acting Administrator, National Highway Traffic Safety Administration, concerning your revised drawings showing the location of lamps and reflectors on various truck trailers.; Lamps and reflectors mounted as indicated on your three drawings, TTM 42171, would meet the location requirements of FMVSS No. 108.; Sincerely, E. T. Driver, Director, Motor Vehicle Programs, Office o Operating Systems; |
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ID: aiam0678OpenLouis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Environmental Staff, General Motors Technical Center, Warren, Michigan 48090; Louis C. Lundstrom Director Automotive Safety Engineering General Motors Environmental Staff General Motors Technical Center Warren Michigan 48090; Dear Mr. Lundstrom: This is in reply to your letter of March 28, 1972, requestin elaboration of a statement made in the preamble to Motor Vehicle Safety Standard No. 125, Warning Devices. You asked that the NHTSA identify the specific data it used in determining that with respect to wide angle positioning of the device, a lower minimum candlepower than that required by the E.C.E. Provides adequate protection.; As I said in my letter to you of March 27, 1972, in response to similar request, a large amount of material has been placed in this public docket as background for the rulemaking action. All of this material has been carefully studied by the NHTSA, and together with the expertise and judgment of NHTSA personnel, relied on in reaching the decisions involved in issuing this standard. In informal rulemaking proceedings, the decisions are based on the total weight of the agency's knowledge, not on particular items of information.; I will comment, however, that some of the materials relating to th passage that you quoted were submittals from Chrysler Corporation (Nr. 147) and the California Highway Patrol (Nr. 143), and the University of California report on triangle reflector performance (General Reference Nr. 17, Attachment 2).; Sincerely yours, Robert L. Carter, Acting Associate Administrator Motor Vehicle Programs; |
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ID: aiam5180OpenMr. Joseph G. Wilson President The Monmouth Corporation Box 143 Highlands, NJ 07732; Mr. Joseph G. Wilson President The Monmouth Corporation Box 143 Highlands NJ 07732; "Dear Mr. Wilson: Thank you for your letter informing us of th Blu-Lite system, which your company developed. You stated that the system 'protects a vehicle driver from the threat of rear-end collision.' You enclosed a brochure for our information, and would like to demonstrate your system to us. We regret that we cannot accept your offer for a demonstration. In addition, as discussed below, we must advise you that Blu-Lite appears to conflict with both Federal and local laws. Your brochure shows that Blu-Lite is a three compartment lamp, consisting of a center compartment with blue lens (described as 'emergency stop') flanked by two 'red stop lights'. Blue-Lite is shown installed in the rear parcel shelf, apparently as a substitute for the center highmounted stop lamp. In use, Blu-Lite flashes rapidly. The center highmounted stop lamp has been required as original equipment on all passenger cars manufactured on and after September 1, 1985. The effect of Section 108(a)(2)(A) of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1397(a)(2)(A)) is to forbid any manufacturer, distributor, dealer, or motor vehicle repair business from removing the center highmounted stop lamp, and replacing it with any lamp that does not meet the requirements for the center lamp that was original equipment. Blu-Lite does not meet the original equipment specifications in lamp color, which must be red, and in operation, which must be steady-burning. Thus, any manufacturer, distributor, dealer, or motor vehicle repair business who substituted Blu-Lite for an original equipment center highmounted stop lamp would appear to be in violation of Section 108(a)(2)(A). The Safety Act does not prohibit a vehicle owner from installing Blu-Lite, or any other person, including manufacturers, distributors, dealers, and motor vehicle repair businesses, from installing it on a passenger car manufactured before September 1, 1985. However, the legality of its use must be determined under state laws. It is our impression that many states allow the use of blue lamps only on emergency vehicles. Additionally, many states have laws similar to the Federal one as it relates to the performance and use of the center highmounted stop lamp. If you wish to confirm this, we suggest that you consult the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203. Sincerely, John Womack Acting Chief Counsel "; |
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ID: aiam2645OpenMr. James Tydings, Specifications Engineer, Thomas Built Buses, Inc., 1408 Courtesy Road, P.O. Box 2450, High Point, NC 27261; Mr. James Tydings Specifications Engineer Thomas Built Buses Inc. 1408 Courtesy Road P.O. Box 2450 High Point NC 27261; Dear Mr. Tydings: This responds to your August 31, 1977, letter asking whether a New Yor state requirement mandating the installation of both side emergency doors and rear emergency doors in school buses would mean that both emergency doors would be required to comply with the school bus exit specifications in Standard No. 217, *Bus Window Retention and Release*.; The NHTSA has determined previously that only those exits required b S5.2.3 must meet the requirement specified for school bus emergency exits in Standard No. 217. Paragraph S5.2.3 requires either a rear emergency door or a side emergency door and a rear push out window. The side emergency door to which you refer is installed in addition to a rear emergency door. The presence of the rear emergency door, alone, satisfies the requirements of S5.2.3. Therefore, a side emergency door is not required by the standard and need not meet the specifications for school bus emergency exits. Emergency exits installed in school buses beyond those required in S5.2.3 must comply with regulations applicable to emergency exits in buses other than school buses. These requirements are also detailed in Standard No. 217.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam3957OpenMr. James H. Westlake, Associate Director, American Truck Dealers Division, National Automobile Dealers Association, 8400 Westpark Drive, McLean, VA 22102; Mr. James H. Westlake Associate Director American Truck Dealers Division National Automobile Dealers Association 8400 Westpark Drive McLean VA 22102; Dear Mr. Westlake: This is in reply to your letter of February 25, 1985, to Mr. Stephe Wood of this office asking the following three questions about rebuilding and remanufacturing heavy duty trucks.; >>>'1) When rebuilding a used truck with a glider kit, it is ou understanding that the process is considered 'rebuilding' when the three major components (engine, transmission and rear axle) are reused in the rebuilding process. If one or more of these major components is new, does the production of the truck chassis change its legal character from 'rebuilding' to 'first stage manufacturer'?'<<<; Neither the National Traffic and Motor Vehicle Safety Act ('the Act' nor the Federal Motor Vehicle Safety Standard ('safety standards') contain the terms 'rebuilding' and 'first stage manufacturer'. Your question, however, is clear: when new and used components are used in rebuilding a heavy truck, at what point does the truck become a 'new' vehicle which must comply with all safety standards that apply to trucks.; The agency's regulation on *Combining new and used components*, 49 CF 571.7(e), provides:; >>>'When a new cab is used in the assembly of a truck, the truck wil be considered newly manufactured for purposes of compliance with the safety standards and other provisions of the Act unless the engine, transmission, and drive axle(s) (as a minimum) of the assembled vehicle are not new, and at least two of these components were taken from the same vehicle'.<<<; Thus, in terms of your question, if the three major components ar reused in the rebuilding process and at least two of the three came from the same vehicle, the Federal motor vehicle safety standards do not apply even if a new cab is used. But if one of the three components is new, or if all are used and came from three different motor vehicles, then the standards apply and the truck must meet them, and be certified as meeting them, upon final assembly.; Your reference to 'first stage manufacturer' implies that there may b rebuilding fact situations in which the process is completed by a person other than the manufacturer who initiated it. If the rebuilt truck is 'new', then its assemblers are subject to 49 CFR Part 568 *Vehicle (sic) Manufactured in Two or More Stages*. If the truck meets the definition of 'incomplete vehicle', then the 'incomplete vehicle manufacturer' is required to furnish the specified compliance information necessary for certification to the 'intermediate stage manufacturer' or the 'final stage manufacturer' as the case may be (sec. 568.3).; >>>'2) When a truck chassis is built by a dealer and legally classifie as 'new manufacturing' what federal regulations must be complied with that do not apply when the vehicle is considered rebuilt?'<<<; As indicated above, the truck must be completed to comply with al safety standards that apply to trucks and be certified by its assembler as so conforming in accordance with Part 567 *Certification*. If more than one party is involved in the remanufacturing process, each party is subject to Part 568. In addition, any party remanufacturing a truck that must be certified as conforming is required to file a statement in the form prescribed by Part 566 *Manufacturer Identification*.; >>>'3) What penalties exist for failing to comply with these Federa regulations?'<<<; As provided by section 109(a) of the act, any person violating an provision of the Act or a regulation issued thereunder is subject to a civil penalty of up to $1000 for each violation, up to $800,000 for any related series of violations. In addition, under Section 110(a) of the Act, the agency may seek to restrain the manufacture, sale, offer for sale, introduction, or delivery for introduction into interstate commerce of any rebuilt truck that should have met Federal motor vehicle safety standards but in fact did not do so. Also, section 154 of the Act requires manufacturers to conduct recall campaigns and remedy any non-compliances with applicable safety standards.; I hope this information is helpful. Sincerely, Jeffrey R. Miller, Chief Counsel |
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ID: aiam0228OpenMr. Jackson Decker, Chief, Product Engineer, E. E. Etnyre and Company, 200 Jefferson Street, Oregon, IL 61061; Mr. Jackson Decker Chief Product Engineer E. E. Etnyre and Company 200 Jefferson Street Oregon IL 61061; Dear Mr. Decker: This is in reply to your letter of March 27, 1970, to the Director Office of Performance Analysis, now changed to the Office of Compliance, in which you pose the following question: 'In the case of a body mounted on a chassis- cab which chassis-cab has had previous service as a completed vehicle, is it permissible to omit certification as required under Part 367, 49 C.F.R., since it is beyond the knowledge of the body manufacturer to ascertain compliance with the pertinent chassis-cab standards? The vehicle manufacturer will perform his work in compliance with current standards insofar as practicable.'; The answer to your question is yes. At this time it is permissible t omit certification in the case you have described in your question, since the motor vehicle safety standards do not apply to domestic used vehicles. In the event, however, that you use an item of automotive equipment for which there is an applicable standard, such as glazing material, you are required to certify in accordance with Section 114 of the National Traffic and Motor Vehicle Safety Act of 1966, as it applies to items of motor vehicle equipment.; Please let us know if we can be of further assistance. Thank you fo your letter and your interest in the programs of the National Highway Safety Bureau.; Sincerely, Rodolfo A. Diaz, Acting Associate Director, Motor Vehicl Programs; |
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ID: aiam2215OpenMr. 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: This is in reply to your letter of March 10, 1976, asking whethe S4.6(b) of Motor Vehicle Safety Standard No. 108 allows a flashing side marker lamp 'in any location on the side of a motor vehicle without having to comply with State law pertaining to side-mounted turn signals.'; S4.6(b) allows side marker lamps to flash for signalling purposes Since a flashing side marker lamp is in essence a side turn signal lamp, any State regulation specifically addressed to location and flash rate of side turn signals would appear to be preempted by Standard No. 108, if the side marker lamp is combined with a side turn signal lamp. If the side turn signal lamp is a separate lamp, then it would be subject to State regulation.; Your inquirer wishes to install 'a side marker lamp on each side nea the middle of the trailer to flash with the turn signal lamps.' If the lamp to be added is not the intermediate side marker lamp required by Standard No. 108 for trailers whose length is 30 feet or more, it would be governed by the California Vehicle Code and not preempted.; We intend to address the issues of side mounted turn signal lamps flashing side marker lamps, and flashing headlamps in a rulemaking proposal whose publication is imminent, and I will include your letter in the Docket as a comment to be considered.; Yours truly, Stephen P. Wood, Assistant Chief Counsel |
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ID: aiam4512OpenMr. Michael Rose Technical Secretary for Executive Director Jamaica Bureau of Standards 6 Winchester Road Kingston l0 JAMAICA; Mr. Michael Rose Technical Secretary for Executive Director Jamaica Bureau of Standards 6 Winchester Road Kingston l0 JAMAICA; Dear Mr. Rose: This responds to your letter, addressed to the Directo of the Office of the Federal Register, concerning Federal Motor Vehicle Safety Standard No. 109, New Pneumatic Tires. The National Highway Traffic Safety Administration (NHTSA) is the Federal agency which issued and administers that standard. Your questions are addressed below. By way of background information, NHTSA issues Federal motor vehicle safety standards under the National Traffic and Motor Vehicle Safety Act, l5 U.S.C. l38l et seq. The term 'motor vehicle safety standard' is defined by the Act as 'a minimum standard for motor vehicle performance, or motor vehicle equipment performance, which is practicable, which meets the need for motor vehicle safety and which provides objective criteria' (section l02(2)). NHTSA does not grant approvals of motor vehicles or motor vehicle equipment. Instead, section ll4 of the Act requires manufacturers to certify compliance of each motor vehicle and item of equipment with all applicable standards. The Act requires that manufacturers exercise 'due care' to ensure that their products conform to each applicable standard (section 108(b)(l)). I will address your first two questions together. The questions are: l. In the clause dealing with Test Sample, why are the batch size and sample size not mentioned? 2. Why does the standard make no reference to the frequency of testing. As indicated above, Standard No. 109 is a minimum performance standard. All tires must be capable of meeting the standard's requirements. The purpose of the test sample paragraph (S4.2.2.l) in Standard No. 109 is to indicate that a test set for a compliance test consists of three tires. One tire is checked for physical dimensions and is then subjected to resistance to bead unseating and strength, in sequence. The second tire is subjected to the endurance test, and the third tire is subjected to the high speed test. Paragraph S4.2.2.l is not intended to address the question of how many sets of tires a manufacturer should test as a surveillance procedure during production or what batch size the test sets should be drawn from. A manufacturer is not required to conduct any particular frequency of testing or even to run the actual tests specified by Standard No. 109. Instead, a manufacturer must take whatever steps are necessary to ensure that each of its tires, if tested according to the requirements of the standard, would meet those requirements. (For test purposes, however, any one given tire would only be subjected to one of the three test sequences discussed above.) Since Standard No. 109 includes a number of specific test requirements, it is likely that a manufacturer would find it necessary to do some testing in order to ensure that a tire complied with the standard. For enforcement purposes, NHTSA would test a tire according to the specific test requirements of Standard No. 109. Your third question is as follows: 3. Why does the standard make no reference to tolerances for tyre concentricity? NHTSA's standards cover aspects of performance for which the agency has determined there is a safety need. To date, NHTSA has not determined that there is a need for requirements covering tire concentricity tolerances. We note that tire concentricity appears to be primarily an issue of occupant comfort rather than safety. I hope this information is helpful. Sincerely, Erika Z. Jones 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.