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: aiam3160OpenMr. Edward F. Tannery, Theodore Bargman Company, 129 Industrial Avenue, Coldwater, MI 49036; Mr. Edward F. Tannery Theodore Bargman Company 129 Industrial Avenue Coldwater MI 49036; Dear Mr. Tannery: This responds to your recent letter asking whether doors on aftermarke top covers for American Motors Jeeps would have to comply with Safety Standard No. 206, *Door Locks and Door Retention Components*.; Safety Standard No. 206 applies to passenger cars, trucks an multipurpose passenger vehicles, which would include Jeeps. The standard applies only to completed vehicles, however, and not to aftermarket motor vehicle equipment. Therefore, the doors on aftermarket Jeep top covers would not have to have locks. Further, doors on new Jeep vehicles would also not have to comply with the standard if they are 'designed to be easily attached to or removed from' the vehicle, as provided in section S4 of the standard.; Please contact Hugh Oates of my office if you have any furthe questions.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam4328OpenMr. T. Chikada, Manager, Automotive Lighting, Engineering Control Department, Stanley Electric Co., Ltd., 2-9-13, Nakameguro, Meguro-ku, Tokyo 153, Japan; Mr. T. Chikada Manager Automotive Lighting Engineering Control Department Stanley Electric Co. Ltd. 2-9-13 Nakameguro Meguro-ku Tokyo 153 Japan; Dear Mr. Chikada: This is in reply to your letter of March 4, 1987, with reference t aiming adjustment of fog lamps. We understand that Stanley is developing a fog lamp and replaceable bulb headlamp with a common lens and housing. Since the portion of the housing also functions as a reflector, the fog lamp moves simultaneously with the headlamp in aiming adjustment. In your view, it will not impair the effectiveness of the headlamp, and you ask for confirmation that the lamp 'is acceptable in the U.S.A.; Federal Motor Vehicle Safety Standard No. 108 contains no requirement for a fog lamp, and would prohibit it only if it impaired the effectiveness of any other lamp mounted on the front of a vehicle that is required by the standard. Assuming that the fog lamp does not impair the effectiveness of the headlamp, its installation would not crate a noncompliance with Standard No. 108. However, in the absence of a Federal standard on fog lamps, the individual States may establish their own requirement for fog lamps. We are unable to advise you whether this design would be acceptable in each of the 50 States, and other jurisdictions in which the Federal standards must be met, we can only advise you that it does not appear prohibited by Federal law.; The American Association of Motor Vehicle Administrators (AAMVA). 120 Connecticut Avenue, N.W., Washington, D.C., 20036 may be able to advise you as to state laws relevant to your design.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3117OpenMr. J. B. H. Knight, Chief, Car Safety and Regulations Engineer, Rolls-Royce Motors Limited Car Division, Crewe Cheshire CW1 3PL, ENGLAND; Mr. J. B. H. Knight Chief Car Safety and Regulations Engineer Rolls-Royce Motors Limited Car Division Crewe Cheshire CW1 3PL ENGLAND; Dear Mr. Knight: This is in response to your letter of August 17, 1979, regarding th requirements in Federal Motor Vehicle Safety Standard (FMVSS) No. 208, Occupant Crash Protection, pertaining to the emergency release warning system for automatic belts.; Paragraph S4.5.3.3(b)(1) of the standard requires an audible an visible warning if the driver's automatic belt system is not in use, as determined by the belt latch mechanism not being fastened. On one of your automatic belt designs the latch mechanism consists of a pivoting bar which slips through a small stitched loop on the end of the belt webbing. You note that this latch mechanism can be fastened without the webbing being connected to the pivot bar, and that in such a case the warning system would not operate even though the belt is not in use. Therefore, you ask if you can install a switch in the automatic belt retractor to detect when insufficient webbing is extended from the retractor to engage with the latch on the door frame. You ask if such a system could be used as an alternative to the existing requirement or, if the standard could be amended to allow the alternative.; In answer to your question, a switch in the retractor of an automati belt system would not satisfy the current warning system requirement if the system did not also include a switch in the emergency release latch mechanism. Further, the Agency does not believe that it is necessary to amend the standard to allow such an alternative. Although it may be true that the existing warning system could be defeated in a belt system such as you describe, the same is true with most warning system requirements. For example, if the standard provided the alternative you suggest, the automatic belt could be 'tied-off' after sufficient webbing was withdrawn from the retractor and the warning system would be defeated. As you know, this method has been used to defeat the warning systems of many manual belts in the past. Therefore, we believe the existing requirement is sufficient to warn vehicle occupants that their automatic belt has been released and should be reconnected.; The 'pivot-bar' release mechanism described in you letter appears t comply with the requirements of the standard. However, we believe that the bar should remain in the released position after the belt webbing has been removed so that the warning system will activate. In other words, we assume that the pivot bar does not re-latch automatically after being released but, rather, requires manual re-latching by the occupant.; Regarding your third question we have enclosed, for your information Notice 14, Docket No. 1- 18, which establishes the new requirements related to controls and displays.; Sincerely, Ralph J. Hitchcock, Chief, Crashworthiness Division, Offic of Vehicle Safety Standards; |
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ID: aiam4778OpenMs. Carol Zeitlow Manager, Engineering Services Oshkosh Truck Corporation P.O. Box 2566 Oshkosh, WI 54903-2566; Ms. Carol Zeitlow Manager Engineering Services Oshkosh Truck Corporation P.O. Box 2566 Oshkosh WI 54903-2566; Dear Ms. Zeitlow: This is in reply to your letter of August 1, 1990, t Taylor Vinson of this Office, with respect to Motor Vehicle Safety Standard No. 108. You ask for confirmation that 'the hazard warning light should always over-ride the stop lamp' when they are 'together on a vehicle.' I am pleased to provide that confirmation. Under the relevant SAE materials on stop lamps that are incorporated by rference in Standard No. 108, when a stop signal is optically combined with the turn signal, the circuit shall be such that the stop signal cannot be turned on if the turn signal is flashing. Because the hazard warning system operates through the turn signal lamps, the stop signal cannot be turned on in an optically combined lamp if the hazard system is in use. You have also noted that in your version of Standard No. 108, no reference is made to SAE Standard J1395. It was not until May 15 of this year that Standard No. 108 was amended to incorporate SAE J1395 (with an effective date of December 1, 1990). I enclose a copy of that amendment for your information. If you have any further questions, we shall be pleased to answer them. Sincerely, Paul Jackson Rice Chief Counsel; |
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ID: aiam1080OpenMr. T. Hiramine, Director, Takata Kojyo Co., Ltd., No. 10 Mori Building, 28 Sakuragawa-Cho, Nishikubo, Shiba, Minato-Ku, Tokyo, Japan; Mr. T. Hiramine Director Takata Kojyo Co. Ltd. No. 10 Mori Building 28 Sakuragawa-Cho Nishikubo Shiba Minato-Ku Tokyo Japan; Dear Mr. Hiramine: Thank you for your letter of February 24, 1973, to Mr. Franci Armstrong, requesting various interpretations of Standards No. 208 and No. 209, with respect to safety belt systems.; Your first question, referenced to Figure No. 1 of the enclosure wit your letter, relates to the required strength of the webbing in the case where two widths are connected together in an upper torso assembly. Under the webbing strength requirements of S4.2(b) of Standard No. 209, both pieces of webbing in the upper torso restraint must, individually, meet a 4,000 pound strength test. Under the assembly performance requirements of S5.3(b) of Standard NO. 209, a common pelvic and upper torso restraint must meet a 3,000 pound strength test. The latter would be true regardless of whether sewing or other means is used to make the belt assembly.; Your second question, referenced to Figure 2 of the enclosure, relate to the bolt strength required in the belt assembly anchorage. Under the provisions of S4.1(f), 'equivalent hardware' is permissible in lieu of the 7/16 inch bolts. In such a case, the tests required under S4.3(c), as prescribed under S5.2(c), would be performed on the entire equivalent hardware, rather than on the individual components (bolts).; With respect to your third question, concerning the acceptability o belts that do not conform to the elongation requirements of Standard No. 209, our reply is that under the present circumstances such webbing would not conform to either Standard No. 208 or Standard No. 209. As a result of the decision by the United States Court of Appeals for the Sixth Circuit in *Ford* v. *NHTSA*, belts installed under Standard No. 208's third option in 1973 (S4.1.2.3) will have to conform to Standard No. 209. Unless Standard No. 209 is amended with respect to its elongation requirements, therefore, energy absorbing webbing of the type you describe will not be permitted in 1974 cars,; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
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ID: aiam4282OpenMr. Robert W. Christian, Executive Director, Wisconsin School Bus Association, P.O. Box 168, Sheboygan, WI 53082-0168; Mr. Robert W. Christian Executive Director Wisconsin School Bus Association P.O. Box 168 Sheboygan WI 53082-0168; Dear Mr. Christian: This responds to your letter to former Chief Counsel Frank Bernd asking about our school bus regulations. I hope you find the following discussion helpful and regret the delay in providing it.; You ask whether our school bus safety standards apply to vehicle designed to carry 11 or more persons but which are actually used to transport nine or fewer students. According to your letter, Wisconsin does not consider 12 and 15-passenger vans as 'school buses' if they are used to carry only nine or fewer students. You ask also whether these vehicles must be painted and identified as school buses.; Because your letter raises several issues concerning our school bu regulations, I believe some background information might be helpful in answering your questions. Our agency has two sets of regulations that apply to school buses. The first set, issued under the authority of the National Traffic and Motor Vehicle Safety Act ('Vehicle Safety Act'), applies to the manufacture and sale of new motor vehicles and includes the Federal motor vehicle safety standards for school buses. The second set of 'regulations' for school buses was issued under the authority of the Highway Safety Act. Those regulations or 'highway safety program standards,' are recommendations from this agency to the states for developing their highway safety programs and includes guidelines on school bus color and marking.; The Vehicle Safety Act establishes requirements that manufacturers an sellers of new school buses must meet. It requires manufacturers to certify that their vehicles must meet all Federal safety standards applicable to 'school buses.' Further, the Act requires any person selling a new bus for pupil transportation purposes to sell a bus that complies with our motor vehicle safety standards for 'school buses' or be potentially subject to fines under Federal law for selling noncomplying vehicles. Under the regulations we issued under the Vehicle Safety Act, a new vehicle designed for carrying 11 or more persons (including the driver) is considered a 'bus,' and is considered to be a 'school bus' if sold for school-related purposes.; The first issue you raise is whether it is permissible under Federa law to transport students in 12 or 15-passenger vans which do not comply with Federal school bus safety standards, if the number of students transported is limited to nine or fewer. The answer to your question is yes. Please note that, as further explained below, the fact that the number of students actually carried on the bus is restricted to nine or fewer has no effect on the permissibility of the activity you described.; School bus users such as a school or school district may use thei 'plain (noncomplying) vans' to carry students. This is because the responsibility to comply with Vehicle Safety Act requirements falls upon the manufacturers and sellers of new school buses, and not the users of the vehicles. While persons selling new 12 or 15 passenger vans for pupil transportation purposes are obligated to sell buses which conform to our school bus safety standards, the Act imposes no requirement on school bus users that requires them to transport students in complying school buses.; You ask whether the phrase 'designed for carrying' in our 'bus definition refers to the number of seating positions the vehicle is manufactured with, or the number of passengers actually carried on the vehicle at any one time. The phrase 'designed for carrying' refers to the number of seating positions in the vehicle. NHTSA determines the passenger capacity of a vehicle by the vehicle's actual seating capacity, which is determined by identifying the number of designated seating positions in the vehicle. If a van is manufactured to carry 12 or 15 passengers, it is a 'bus' and must comply with school bus safety standards if sold to carry school children. For the purposes of Federal law, whether a school bus user will carry only nine or fewer students in its 12 or 15-passenger van has no affect on the seller's obligation to sell complying school buses.; Further, Federal law applies to the sale of the new 12 or 15-passenge school vans regardless of whether Wisconsin considers these vehicles 'school buses' under state law. I believe this was explained to your association in the June 20, 1983 letter from Mr. Berndt concerning state 'school bus' definitions. Mr. Berndt explained that 'the decision of a state not to adopt the Federal classification has no effect on the application of the Federal school bus standards to that vehicle.' Thus, even if new 12 or 15-passenger vans are not 'school buses' under state law, persons selling such vehicles for pupil transportation are obligated under Federal law to sell complying school buses.; Your next question asks whether 12 or 15-passenger vans must be marke and painted as school buses even if they transport 9 or fewer students. This question concerns the highway safety program standards which I referred to earlier in this letter. Highway Safety Program Standard No. 17, *Pupil Transportation Safety * (copy enclosed), includes recommendations for the operational aspects of state pupil transportation programs, such as school bus color and marking, vehicle maintenance and driver training. Since the decision to adopt Standard No. 17's recommendations is left to each state, Wisconsin law would determine whether the vans must be marked and painted as school buses.; Your final question asks where you can find the Federal standard relating to 'motor buses.' Part 571 of Title 49 of the Code of Federal Regulations contains the Federal Motor Vehicle Safety Standards applicable to buses, school buses and other types of motor vehicles. As with the manufacture of school buses, manufacturers of buses must certify that their vehicles comply with all applicable Federal safety standards. I have enclosed information on how you can order a copy of our standards.; I hope this information is helpful. Please contact us if you hav further questions.; Sincerely, Erika Z. Jones, Chief Counsel |
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ID: aiam3547OpenMr. G. K. Blair, Sales Manager, Norton Motors (1978) Limited, Lynn Lane, Shenstone, Lichfield, Staffordshire WS14OEA, England; Mr. G. K. Blair Sales Manager Norton Motors (1978) Limited Lynn Lane Shenstone Lichfield Staffordshire WS14OEA England; Dear Mr. Blair: This is in reply to your letter of March 5, 1982, asking whether proposed motorcycle taillamp assembly would comply with Motor Vehicle Safety Standard No. 108.; As you point out, the standard requires a minimum distance of 4 inche edge to edge between turn signal lamps and stop/tail lamps. Since you state that you cannot achieve this with your design, the lamp as currently designed would not be permitted by our standard. This will confirm the oral interpretation provided by Taylor Vinson of this office when you telephoned on March 22.; You will be interested to know that we are presently studying side an rear conspicuity of motorcycles. This research is being conducted by Ketron in Philadelphia, Pennsylvania, and the final report is expected in July 1982 should you wish to obtain a copy of it from us.; As you requested confidential treatment of your engineering drawing, w are returning it to you.; Sincerely, Frank Berndt, Chief Counsel |
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ID: aiam5539OpenMr. Takashi Adachi Manager Ichikoh Industries, Ltd. North American Liaison Office 555 Briarwood Circle, Suite 190 Ann Arbor, MI 48108; Mr. Takashi Adachi Manager Ichikoh Industries Ltd. North American Liaison Office 555 Briarwood Circle Suite 190 Ann Arbor MI 48108; Dear Mr. Adachi: This is in reply to your letter of March 14, 1995, t Richard Van Iderstine of this agency, asking for an interpretation of Motor Vehicle Safety Standard No. 108 as it applies to a reflex reflector design that you attached. This design shows a single reflector 2 inches in height mounted behind a clear outer lens which is bisected horizontally by an opaque strip 6mm (.25 in.) wide, giving the impression from the exterior of two reflectors, one .75 in. high above the divider, and one that is 1.00 in. in height, below the divider. You have asked whether the 'structure of the reflex reflector conforms to FMVSS 108,' and whether photometric conformance is judged with respect to the single reflector crossed by the opaque strip, or whether both the upper and lower portions of the bisected reflector must meet the photometric specification. Standard No. 108 is a performance standard, not a design standard. The standard does not specify any requirements concerning the structure of reflectors. The applicable requirements for reflex reflectors are those of SAE Standard J594f Reflex Reflectors January 1977, which Standard No. 108 incorporates by reference. Your reflector should be tested as a single reflector according to the procedures set forth in J594f. If the reflector does not meet the photometric performance requirements of that standard, you may add sufficient reflective elements to the reflector design until conformance is achieved. There is no need to test the upper and lower portions as separate reflectors. If you have any further questions, you may refer them to Taylor Vinson (202) 366-5263 of this Office. Sincerely, John Womack Acting Chief Counsel; |
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ID: aiam2706OpenMr. Howard Gould, Gould, Reichert & Strauss, 2613-20 Carew Tower, Cincinnati, OH 45202; Mr. Howard Gould Gould Reichert & Strauss 2613-20 Carew Tower Cincinnati OH 45202; Dear Mr. Gould: This confirms the substance of your November 2, 1977, meeting wit Roger Tilton of my staff concerning the applicability of the new Federal school bus safety standards to common carriers used in urban and rural transportation.; You indicated in that meeting that you thought that the effect of th Urban Mass Transportation Administration's grant program to rural transit authorities would be to phase out the standard yellow school bus in favor of transporting children on rural transit buses. This situation would result in the avoidance of the Federal school bus regulations.; It is the opinion of the National Highway Traffic Safety Administratio (NHTSA) that buses used by rural transportation districts to transport school children do not qualify for the limited exception from the school bus safety standards accorded to urban transportation common carriers.; The agency has traditionally excluded urban common carrier buses fro the school bus requirements to allow transportation of school children on existing urban transportation facilities. The agency has never extended this exclusion to rural common carrier buses. In our notice on the redefinition of school bus (40 FR 60033) the NHTSA indicated that only urban transit buses would fall within the ambit of this limited exception. By that action, the agency intended to avoid the artificial development of rural transportation authorities that would result in the avoidance of the Federal school bus regulations.; In another comment you criticized the agency's adoption of a 'us definition' for the applicability of the school bus regulations since the application of such definition depends upon the sales transaction to establish the intended use of the vehicle. You allege that enforcement of regulations dependent upon the sales transaction cannot be achieved.; The agency adopted the 'use definition' for the regulation of schoo buses as a result of a Congressional directive in the Motor Vehicle and School Bus Safety Amendments of 1974 (Pub. L. 93-492). Congress defined school bus in a manner that requires the use of a vehicle to be considered. Accordingly, the agency must employ the 'use definition' in regulating school buses. The NHTSA does not agree that the new regulations are unenforceable as a result of this regulatory approach. Enforcement of these regulations will be as vigorous as the enforcement of any other NHTSA regulation.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam1829OpenHonorable Mark Andrews, House of Representatives, Washington, DC 20515; Honorable Mark Andrews House of Representatives Washington DC 20515; Dear Mr. Andrews: This responds to your February 18, 1975, request for information i behalf of a constituent, concerning any Federal regulation which might require bulk oil trucks to have a 120-inch wheelbase and be equipped with certain wheels, tires, and axles.; Neither the National Highway Traffic Safety Administration (NHTSA) no the Bureau of Motor Carrier Safety of the Federal Highway Administration has issued a safety standard which requires a certain wheelbase or the components listed by your constituent.; NHTSA has issued Standard No. 121, *Air brake systems*, whic establishes minimum performance requirements for air-braked vehicles. A major requirement is that an air-braked vehicle must be capable of stopping within a distance that is comparable to average passenger car performance. This requirement is intended to reduce the incompatibility in braking performance between heavy trucks and passenger cars which must share the nation's highways.; Manufacturers are free to choose any design which permits thei vehicles to stop in the required distance. It is possible that the manufacturer of your constituent's vehicle has found that a longer wheelbase and stronger axles, brakes, wheels, and tires are necessary to insure that the vehicle is capable of consistently stopping without loss of control in a distance comparable to the average passenger car. We consider the modification of vehicles in this fashion to be a significant contribution to motor vehicle safety.; Sincerely, James C. Schultz, Chief Counsel |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.