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: nht78-1.38OpenDATE: 04/25/78 FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA TO: Wayne Corporation TITLE: FMVSS INTERPRETATION TEXT: This responds to your February 28, 1978, letter asking whether portions of your van-type school bus have to comply with the head protection zone requirements of Standard No. 222, School Bus Passenger Seating and Crash Protection. You enclosed pictures showing portions of the bus designated in pink and yellow and question the standard's applicability to them. The head protection zone requirements do not apply to portions of the school bus that are considered part of the bus sidewall. The National Highway Traffic Safety Administration considers the sidewall to include those surfaces that run parallel to the outboard edge of a forward facing seat. Accordingly, the portions of your bus designated in yellow in the pictures need not comply with the requirements since they are part of the bus sidewall structure. The pink portions of your photographs represent part of the bus structure that is perpendicular to the bus sidewall. The NHTSA does not consider them to be part of the bus sidewall structure. Therefore, since they fall within the head protection zone they must comply with all of the requirements applicable to that zone. Sincerely, ATTACH. PHOTO A VIEW LOOKING FORWARD TOWARD RIGHT-HAND FRONT SERVICE DOOR. (Graphics omitted) PHOTO B VIEW LOOKING FORWARD TOWARD LEFT-HAND FRONT DRIVER'S AREA. (Graphics omitted) Wayne Corporation February 28, 1978 Office of Chief Counsel National Highway Traffic Safety Administration Dear Sir: This inquiry concerns Federal Motor Vehicle Safety Standard 222, School Bus Passenger Seating and Crash Protection. The enclosed photographs marked and labeled as follows: Photo A - View looking forward toward right-hand front service door, and Photo B - View looking forward toward left-hand front driver's area, show interior views of the Wayne Busette school bus described in the enclosed Wayne Busette specification sheet. The interior surfaces of the bus colored pink and yellow in Photos A and B fall within the head protection zone defined in FMVSS 222, S5.3.1.1. For purposes of clarity, the front row of passenger seats had been removed before the pictures were taken. Please advise whether or not the areas colored pink and yellow in Photos A and B are subject to the requirements of FMVSS 222, S5.3.1.2, Head Form Impact Requirements, and S.5.3.1.3, Head Form Force Distribution. In responding to this inquiry, we ask that consideration be given to the first paragraph of S5.3.1.1, "The head protection zones in each vehicle are the spaces in front of each school bus passenger seat which are not occupied by bus sidewall, window, or door structure and which . . . ." Wayne believes that while the pink and yellow colored areas are located in front of a passenger seat, these surfaces should be classified as part of the bus sidewall, window, and door structure and, therefore, are excluded from the requirements of S5.3.1.2 and S5.3.1.3. Your prompt attention and early reply to this inquiry would be greatly appreciated. Sincerely yours, Robert B. Kurre Director of Engineering [Enclosures Omitted] |
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ID: aiam4472OpenMr. Donald Smith Chief Inventor New Innovative Systems 1047 E. Vernon Road Philadelphia, PA 19146; Mr. Donald Smith Chief Inventor New Innovative Systems 1047 E. Vernon Road Philadelphia PA 19146; Dear Mr. Smith: This is in reply to your recent undated lette regarding the 'Highway Automatic Communications Indicator (HACI)', as supplemented by a telephone conversation between you and Stephen Wood of my staff on December 20, l988. You have asked for approval of your device. The HACI 'will display, via a transparent display screen mounted in the rear window, pre-programmed distress messages, activated only when with the automobile is at a complete standstill.' The diagram of the display alert indicates that the message would appear in the middle of the rear window, rather than at the bottom of the window where the lamp would be. When not activated, the device would be transparent. It would be activated by a special switch, not by the brake pedal. It is our understanding that the HACI would be activated only when the vehicle is stationary, and is not wired into the brake light or hazard light system. The National Highway Traffic Safety Administration has no authority to approve or disapprove individual inventions or devices. We can, however, advise you as to the relationship of the HACI to the Federal motor vehicle safety standards and the National Traffic and Motor Vehicle Safety Act under the authority of which the standards are issued. These standards must be met at the time a vehicle is sold to its first purchaser, and persons other than the purchaser may not modify a vehicle after its sale in a manner that, in essence, renders it noncompliant with any standard. There are three standards potentially affected by the HACI. The first is the lighting standard, Standard No. 108. Since the HACI's display screen is mounted in the rear window, a problem could arise if the center high mounted stop lamp required by Standard No. 108 is also mounted in that area. The HACI is permissible as original vehicle equipment as long as it does not impair the effectiveness of the high mounted lamp, or any other lamp required by Standard No. 108. While this determination is the responsibility of the vehicle manufacturer (or dealer, if the HACI is installed after vehicle manufacture but before sale to its first purchaser) in the first instance, it appears to us that the effectiveness of the high mounted lamp would not be impaired. We base this conclusion on our understanding that the message would appear in the middle of the rear window, instead of at the bottom of the window where the lamp would be and that it would apparently be activated only when the vehicle was stationary, such as parked on the side of the road. The second standard potentially affected is Standard No. lll, relating to rearview mirrors. This standard specifies a field of view to be met by the inside rearview mirror, if the mirror does not provide this field of view, an outside mirror on the front seat passenger side must be provided. Since your device is reportedly transparent when not activated, and would be activated only when the vehicle is stationary, it may well be that there is no necessity for the addition of an outside mirror. However, we do not have sufficient information to determine whether the HACI would impede the field of view under all conditions. The third standard potentially affected is Standard No. 205, relating to glazing. This requires, in part, that all glazing in passenger cars have at least 70 percent light transmittance. To the extent that the display screen reduces light transmittance, it could create a noncompliance with this standard. However, because you have indicated that your display screen is transparent, it does not appear likely that any reduction in light transmittance would fall below the specified minimum. With this guidance and your knowledge of the HACI, you should be able to judge whether installation of the HACI either before or after the initial sale of a passenger car might be regarded as creating a noncompliance with a Federal motor vehicle safety standard, or otherwise be in violation of the Act. An official judgment regarding noncompliance or violation is made by the agency only in the context of an enforcement proceeding. In addition, you should be aware that the HACI remains subject to the laws of the individual States. We cannot advise you of its legality under these laws. To obtain an opinion on this matter, you may wish to consult the American Association of Motor Vehicle Administrators, 4600 Wilson Blvd., Arlington, Va. 22203. Sincerely, Erika Z. Jones Chief Counsel; |
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ID: aiam2905OpenMr. F. Michael Petler, Assistant Manager, Safety & Legislation Department, U.S. Suzuki Motor Corporation, P.O. Box 2107, Santa Fe Springs, California 90670; Mr. F. Michael Petler Assistant Manager Safety & Legislation Department U.S. Suzuki Motor Corporation P.O. Box 2107 Santa Fe Springs California 90670; Dear Mr. Petler: This is in response to your letter of August 11, 1978, requesting a interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 127, Speedometers and Odometers.; Standard 127 does not specify that the number '0' appear on the face o the speedometer. It is permissible for you to reletter the '0' mph position to read '5' mph, as the lowest measured speed indicated. This would solve the problem you indicate regarding the relationship of the graduation distance between the 0 and 10 mph to that between 10 and 20, 20 and 30, etc.; The NHTSA has received petitions for reconsideration requesting tha the 10 percent deviation requirement be eliminated. A determination will be made at a later date whether to grant the petitions.; Sincerely, Joseph J. Levin, Jr., Chief Counsel |
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ID: aiam5288OpenMr. Lloyd Boshaw M&L Auto Trim P.O. Box 822 Poway, CA 92074; Mr. Lloyd Boshaw M&L Auto Trim P.O. Box 822 Poway CA 92074; Dear Mr. Boshaw: We have received your letter of January 28, 1993 asking whether you must disconnect an original equipment center highmounted stop lamp when you add an aftermarket spoiler to the deck lid that incorporates such a lamp. I enclose a copy of an interpretive letter we sent David Holscher on August 31, 1990, which remains our position today. In brief, a spoiler lamp will supersede the original equipment center lamp. When the spoiler is installed, Federal law does not dictate whether the original lamp must be disconnected or remain usable. That question is answerable under State law, and we suggest that you consult the Department of California Highway Patrol for its views. If California has no regulation bearing on this problem, we assume that you may either disconnect the original lamp or leave it connected, as your customers desire. Sincerely, John Womack Acting Chief Counsel Enclosure; |
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ID: aiam1706OpenMr. G. W. Overbay, Executive Vice President, Safety Development Systems, Second and Cole Streets, Haines, OR, 97833; Mr. G. W. Overbay Executive Vice President Safety Development Systems Second and Cole Streets Haines OR 97833; Dear Mr. Overbay: In your letter of November 13, 1974 you ask for confirmation of statement you attributed to Taylor Vinson of this office, from a recent telephone conversation, that 'as far as the National Highway Traffic Safety Administration is concerned a green light is legal on the back of an auto.'; Our position is that Federal Motor Vehicle Safety Standard No. 108 doe not forbid installation of a green lamp as original equipment on the rear of a vehicle as long as it does not impair the effectiveness of the required lighting equipment. This means that currently a State may allow a green rear light as optional equipment or forbid its use. Accordingly a green light on the rear of a vehicle is legal or illegal according to the laws of the State where the vehicle is registered.; Yours truly, Richard B. Dyson, Acting Chief Counsel |
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ID: aiam5097OpenMr. David M. Hart President Flushsaver 5440 W. Century Boulevard Los Angeles, CA 90045-5992; Mr. David M. Hart President Flushsaver 5440 W. Century Boulevard Los Angeles CA 90045-5992; Dear Mr. Hart: This responds to your letter of November 16 asking fo 'feedback' on your plan to market a decal called 'Flashit' for installation over a center high-mounted stop lamp. I enclose a copy of an agency letter representative of our advice to inquirers on this subject. Though this letter, to David M. Romansky, dates from September 3, 1987, it remains the agency's position today. Should you wish to contact the American Association of Motor Vehicle Administrators on this subject, please note that its new address is 4600 Wilson Boulevard, Arlington, Va. 22203. Sincerely, Paul Jackson Rice Chief Counsel Enclosure; |
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ID: 06-006094drnOpenColin Pewarchuk, Esq. Vice President, General Counsel New Flyer of America, Inc. 711 Kernaghan Avenue Winnipeg, Manitoba R2C 3T4 CANADA Dear Mr. Pewarchuk: This responds to your request for an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 101, Controls, telltales and indicators. You advise us that your company manufactures and sells transit buses with a gross vehicle weight rating (GVWR) of more than 10,000 pounds (4,536 kg). Based on the information you provided to the agency and the analysis below, I can confirm your understanding framed in your September 19, 2006 letter that as a result of the August 17, 2005 final rule amending FMVSS No. 101 (70 FR 48295), the standard does not regulate, restrict or otherwise affect the use of foot-operated controls. In your letter, you advise us that the majority of transit buses manufactured by your company for sale in the United States include foot-operated controls, including the turn signal control and the high beam control. You stated your belief that most other manufacturers in the transit bus industry, and perhaps manufacturers in the over-the-highway bus or coach industry also manufacture their products with similar foot-operated controls. FMVSS No. 101 specifies that each covered vehicle fitted with a control listed in the standard must meet the requirements of [the] standard for the location, identification, color, and illumination of that control . . . . See S5. In the final rule of August 17, 2005, control was defined at S4 as: the hand-operated part of a device that enables the driver to change the state or functioning of the vehicle or a vehicle subsystem.[1] Since the standards revised definition of control is limited to hand-operated controls, foot-operated controls are not regulated by FMVSS No. 101. We note that the National Highway Traffic Safety Administration explained its intent not to continue to regulate foot-operated controls in FMVSS No. 101 in the preamble to the August 17, 2005 final rule. See 70 FR at page 48298. The standards requirements for foot-operated controls had been very limited. Specifically, FMVSS No. 101 had required that certain foot-operated controls (service brake, accelerator, clutch, high beam, windshield wiper, and windshield washer) must be operable by the driver when restrained by his or her seat belt. In the final rule preamble, we explained that we had proposed and, in the final rule were deciding, to limit the term control (and thus FMVSS No. 101 itself) to hand-operated controls because we were unaware of any current vehicles whose high beam, or windshield washer or wiper controls were foot-operated and because we saw no need, as a practical matter, to state as a regulation that service brakes, accelerators, and clutches be located so as to be operable by the driver. Your letter has made us aware of the continued use in transit buses of foot-operated controls, contrary to the assumption expressed in the recent rulemaking. We note, however, that our rationale for not seeing a need, as a practical matter, to include a requirement that service brakes, accelerators, and clutches be located so as to be operable by the driver also appears applicable to other foot-operated controls needed during driving. That is, we believe it is reasonable to assume that manufacturers that use foot-operated controls necessary for the driving task will locate them such that they are operable by the driver when wearing their seat belt. I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992. Sincerely, Anthony M. Cooke Chief Counsel ref:101 d.3/28/07 [1] This definition was unchanged by the May 15, 2006, response to petitions for reconsideration (71 FR 27964). |
2007 |
ID: nht73-6.15OpenDATE: 04/09/73 FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA TO: Takata Kojyo Co., Ltd. TITLE: FMVSS INTERPRETATION TEXT: Thank you for your letter of February 24, 1973, to Mr. Francis 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 with 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, relates 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" 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 or the individual components (bolts). With respect to your third question, concerning the acceptability of 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. TAKATA KOJYO CO., LTD. February 24, 1973 Francis Armstrong Director, Office of Compliance Motor Vehicle Program National Highway Traffic Safety Administration Attention to; Mr. J. Gilkey Mr. G. Hunter This is to request you to enlighten us upon the under-mentioned questions of ours so as to let us manufacture right seat belts assembly conforming to MVSS. Please note, in this connection, that we have been manufacturing seat belts successfully for many years for installation in the cars destined to the United States. Question # 1. (Please refer to the Figure # 1) As shown on the Fig. #1, we made one shoulder belt connecting one webbing of 2" wide with another of 1" wide by pattern-stitching as the Figure. In this case, what breaking strength is required under S4.2(b) of MVSS 209? Is our belt taken as an assemblied webbings in spite of its connection by stitching? In other words, is 3,000 lbs. the required breaking strength for the said belt? How about in case the 2" webbing is connected with the 1"one with hardwares? Please clarify this case too. Question # 2. (Please refer to the Figure # 2) In compliance with the request of our customers, auto-manufacturers, we are preparing to use two bolts of smaller diameter than 7/16" for fastening to the anchorage. In this case, is each bolt is required to withstand the breaking strength of 5,000 lbs or more? Question # 3. We are planning to use an Energy Absorbent belt for 1974 cars. Our Energy Absorbent belt conforms to the requirement of MVSS 208's S.I. 1,000, but extends more than 40% at 2,500 lbs. In other words, the belt does not conform to MVSS 209. Can our belt be accepted by you, the U.S. authorities when shipped to the U.S. installed in the cars destined to the U.S. markets? Are we right in understanding that MVSS 208 takes precedence of MVSS 209 in this particular case? Thanking you in advance for your kind guidance at your earliest convenience, T. Hiramine, DIRECTOR Enclosed. (Graphics omitted) (Graphics omitted) TAKATA KOJYO CO., LTD. February 26, 1973 Francis Armstrong, Director Office of Standards Enforcement National Highway Traffic Safety Administration, Attention to; Mr. J. Gilkey Mr. G. Hunter Enclosed please find the two copies of sketches numbered as Figure # 1 and Figure # 2. Kindly take a trouble to check whether the two sheets of copied sketches attached to our letter to you dated February 24, 1973 were numbered as Fig. 1 and Fig. 2, respectively. We are afraid if we attached two copies of same number by mistake. If so, please replace the wrong ones by the correct ones enclosed herewith. Provided our originally attached ones were correct ones, please just destroy these copies enclosed herein. Expressing our apologies for inconvenience caused by our oversight, Sincerely yours T. Hiramine Enclosure. (Graphics Omitted) (Graphics Omitted) |
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ID: 13104.jegOpen S. G. Hong Dear Sir or Madam: This responds to your faxed letter asking about Standard No. 208, Occupant Crash Protection. I apologize for the delay in our response. You noted that passenger cars are required to meet Standard No. 208's occupant injury criteria using the air bag only, and also using the air bag plus the manual seat belt. You asked whether passenger cars are also required to meet the standard's injury criteria using the manual seat belt only. The answer to this question is no. You also cited the possibility of people being killed in a crash in which the air bag does not deploy, and where the passenger car does not meet Standard No. 208's occupant injury criteria using the manual seat belt only. You asked who would be "responsible" for the deaths. I note that liability issues are a matter of State law rather than Federal law. We therefore cannot provide an opinion concerning this question. I hope this information is helpful. If you have any further questions, please feel free to contact Edward Glancy of my staff at (202) 366-2992. Sincerely, |
1997 |
ID: nht71-2.13OpenDATE: 03/10/71 FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA TO: Bolt Beranek and Newman, Inc. TITLE: FMVSS INTERPRETATION TEXT: During your visit which Michael Peskoe on March 4, 1971, you indicated that you were desirous of having a reply to the question that you posed in your letter of December 14, 1970, concerning S4.6 of Standard No. 213, without delaying that answer until the response to the entire letter had been prepared. Your question concerning S4.6, which states in part, " . . . [Each] forward-facing child seating system shall have a seat back. The height of the seat back shall be . . .," is whether an adjustable head restraint can be used to meet this requirement provided "(a) it meets the height requirement measured at the lateral center of the head restraint, and (b) it is accompanied, in the instruction sheet, by instructions for adjustment to fit the child." It was intended by paragraph S4.6 that a head restraint could be used to meet the above height requirement, proviced that it meets the other requirements of the standard, such as the head impact protection requirements of S4.10, as well as those you described. |
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.