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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



Displaying 2291 - 2300 of 2914
Interpretations Date

ID: nht91-6.21

Open

DATE: October 14, 1991

FROM: Robert W. Smith -- President, Auto Safety Corporation

TO: Taylor Vinson -- Senior Staff Attorney, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated November, 1991 (est) from Paul Jackson Rice to Robert W. Smith (A38; Std. 108)

TEXT:

My partner and I want to thank you for all the help you gave us during the course of the meeting in your office on August 15, 1990.

Since that meeting we have been continuing the development of our prototype stop lamp license plate frame, in order to conform to all applicable NHTSA standards.

The purpose of this letter is to confirm what we learned at that meeting. Your computer search of Safety Standard #108 data as it would apply to our device, the flashing/steady burning stop lamp, turned up the following:

1. In the case of the Simcox letter (A29, Redbook 3, Erika Z. Jones to Bettie Lou Simcox, October 24, 1986), the use of a flashing/steady burning stop lamp is permissible on a motorcycle. As you'll recall, our embodiment, which complies with specifics of the Safety Standard #108, is a specially designed license plate frame that incorporates a light assembly and a patented (U.S. Patent No. 4,871,945) electronic circuit. (See attached drawings Fig. 1 and Fig. 2)

2. Safety Standard #108 also would allow the use of a flashing/steady burning stop lamp on passenger cars. Specifically, for our purposes, in the embodiment of a license plate frame with built-in lights and circuitry. (Drawing Fig. 1)

3. Safety Standard #108 would permit the use of an auxiliary flashing/steady burning stop lamp which could be mounted on the rear of vans, pickup trucks, and mini vans. (Drawing Fig. 3)

In closing, we again thank you for the help you have given us.

ATTACHMENT

Motor vehicle flashing/steady burning stop lamp license plate frame. (Fig. 1 and Fig. 2) (Graphics omitted)

Auxiliary flashing/steady burning stop lamp. (Fig. 3) (Graphics omitted)

ID: nht68-4.10

Open

DATE: 09/03/68

FROM: AUTHOR UNAVAILABLE; Robert M. O'Mahoney; NHTSA

TO: Officine Alfieri Maserati S.p.A.

TITLE: FMVSR INTERPRETATION

TEXT: This is in responce to your letter of August 8 with reference to compliance of the Maserati automobile with Federal motor vehicle safety standards.

You have asked first of all whether, as a manufacturer of 620 vehicles in 1967, Mascrati may be excused from compliance with some of the Federal standards. The National Traffic and Motor Vehicle Safety Act of 1966, under which Federal standards are issued, was recently amended to authorize a procedure whereby manufacturers of limited production vehicles might petition for examption from the Federal standards. But this procedure is not available to a manufacturer of more than 500 vehicles a year, no matter how few vehicles of that manufacturer are exported to the United States. Consequently Maserati cannot be exempted from any of the Federal standards.

You have also mentioned the difficulties that a small manufacturer face in crash-testing vehicles, and have asked whether the photographs you submitted showing several Mascrasti automobiles which have been involved in front and collisions are acceptable as proof of compliance with Federal standard No. 204 (Steering Control Rearward Displacement - Passenger Cars). I hope the following explanstion will be of assistance to you. The Federal standards do not require crash-testing of vehicles, nor the submission of any data to the Federal Highway Administration for "approval". What is required is that a manufacturer attach a certification on plate to his vehicle stating that the vehicle conforms to all applicable Federal standards on the date of the vehicle's manufacture. How the manufacturer satisfies himself that the vehicle conforms is his own affair; he may have non-crash data or other information which indicates conformance. The Federal Highway Administration, however, may requests this date if through its own investigation it appears that a certification is false or misleading, and that a vehicle does not actually conform to a standard.

I enclose a copy of the latest Federal standards for your guidance.

ID: nht68-4.3

Open

DATE: 08/20/68

FROM: AUTHOR UNAVAILABLE; Charles A. Baker; NHTSA

TO: Calumet Corporation

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of July 22, 1968, to Mr. George C. Nield, concerning the applicability and effective date of Motor Vehicle Safety Standard No. 108.

Standard No. 108 is applicable to new vehicles manufactured on or after the effective date of the standard. Initial Standard No. 108 was published on February 3, 1967, and became effective January 1, 1968. The initial standard is applicable only to vehicle that are 80 inches or more in overall width. Revised Standard No. 108 was published on December 16, 1967, and becomes effective January 1, 1969. The revised standard is applicable to passenger cars, multipurpose passenger vehicles, trucks, buses, trailers and motorcycles, regardless of overall width; however, the special requirements for vehicles that are 80 inches or more in overall width have been identified in the standard. Copies of the initial and revised standard are enclosed for your information.

In reply to your specific questions, information is provided as follows:

1. With respect to your first question, Standard No. 108 is applicable to trailers manufactured for personal use by an individual and for commercial use.

2. With respect to your second question, Revised Standard No. 108, effective January 1, 1969, specifies the lighting requirements for trailers that are less than 80 inches in overall width.

3. With respect to your third question, the regulations of individual States and of the Bureau of Motor Carrier Safety (for vehicles engaged in interstate commerce) presently govern the lighting required on trailers that are less than 80 inches in overall width. Effective January 1, 1969, these trailers will be subject to the requirements of Revised Standard No. 108. Installation and location requirements for the individual lamps are contained in the referenced SAE standards (see Table III of Standard No. 108) and in Table IV of Standard No. 108.

Also enclosed is a copy of the notice on "Certification Requirement," which provides information on the manufacturer's certification of vehicles that are subject to the Federal motor vehicle safety standards.

ID: nht69-1.18

Open

DATE: 02/11/69

FROM: AUTHOR UNAVAILABLE; Clue D. Ferguson; NHTSA

TO: Payne, Barlow and Green, Attorneys at Law

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of January 23, 1969, to William Haddon, Jr., M.D., requesting information on Federal standards for child restraint devices.

I am enclosing a copy of Federal Motor Vehicle Safety Standard No. 209, "Scat Belt Assemblies - Passenger Cars, Multipurpose Passenger Vehicles, Trucks and Buses" which includes requirements for a Type 3 seat belt assembly for persons weighing not more than 50 pounds and capable of sitting upright by themselves.

The technical requirements of the present standard No. 209 were previously included in "Standard for Seat Belts for Use in Motor Vehicles (15 CFR Part 9; 31 F.R. 11528)" which was incorporated by reference in the initial Standard No. 209. I am also enclosing copies of these previous documents.

We are in the process of developing a standard for child car seats and I am enclosing a copy of a recently issued Notice of Proposed Rule Making on this subject. It is important to note that this is only a proposed regulation and the requirements may be modified somewhat when the final rule is published. However, this proposed rule indicates those safety features which are considered to be important for a child car seat.

There are no other existing Federal standards on child restraint systems for use in motor vehicles.

Sincerely,

January 23, 1969

William Haddon, Director National Highway Safety Bureau Department of Transportation

Dear Dr. Haddon:

I am seeking information regarding Federal Standards for Child Restraint Devices and will appreciate your furnishing same to me as soon as it is convenient for you.

I am attempting to measure the adequacy of a particular device that apparently contributed to a child's injury that occurred on May 15, 1968. I do not know the date of manufacture of this device but it is important that I obtain an itemization of minimum standards that have applied for several years.

Sincerely,@@53:426

ID: nht91-1.35

Open

DATE: February 7, 1991

FROM: Billy S. Peterson -- President, Automotive Safety Testing, Inc.

TO: Office of Chief Council, DOT/NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3-8-91 from Paul Jackson Rice to Billy S. Peterson (A37; Std. 108)

TEXT:

This letter is a request for clarification of allowable mounting locations and photometric output requirements for tail/stop lamps on passenger cars.

We have a client who wishes to mount two-part tail/stop lamps on the rear of their vehicle so that one lamp is mounted on the fixed quarter panel and a duplicate lamp is mounted on the trunk lid. The specific question we have is:

Must the minimum photometric requirements be met by the lamp mounted to the quarter panel or may the portion mounted to the trunk lid count toward the photometric requirements?

The confusion arises from a letter from your office to this office dated 1/28/88 which stated that the trunk lid is considered a rigid body panel for purposes of this standard because it is meant to be closed during normal operation and, therefore, the mounting of reflectors and back-up lamps on it is allowed.

Another letter, addressed to Volkswagen of America, dated 7/30/80, states essentially the same thing except it contains the opinion that placement of the tail/stop lamps on the trunk lid may be viewed as a defect in performance, subject to recall. Our interpretation of this letter was that VW had planned to mount lamps only on the trunk lid and not the body quarter panel and this could pose a problem.

Since our client's intention to mount duplicate tail/stop lamps on both the body quarter panel and the trunk lid was not specifically addressed in the earlier letters noted above, this letter serves as a request for clarification of the requisite output requirements associated with that mounting arrangement.

A drawing of the proposed lamp combination is attached to this letter.

Attachment

Drawing of proposed lamp combination (Graphics omitted)

ID: nht91-1.37

Open

DATE: February 11, 1991

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: S.V. Kaaria

TITLE: None

ATTACHMT: Attached to letter dated 1-16-91 from Marvin A. Leach to S.V. Kaaria (OCC 5648); Also attached to letter dated 1-3-91 from S.V. Kaaria to NHTSA

TEXT:

Our Denver Regional Office has forwarded your letter of January 3, 1991, to this Office for reply. You are "the designer of the taillights placed near the rear window of passenger cars." In attempting to negotiate a settlement with vehicle manufacturers, you have been informed that because "elevated brake lights" are required by our agency, the government "should negotiate with me for 1% of replacement cost of these taillights." You have asked that we clarify our position in this matter.

Federal Motor Vehicle Safety Standard No. 108 requires that every passenger car manufactured on or after September 1, 1985, be equipped with a high-mounted stop lamp, mounted on the rear vertical centerline of the vehicle. The only requirement relating to design is that the lens have an effective projected luminous lens area of not less than 4 1/2 square inches, but the standard does not specify the shape of the lens. Within these parameters, manufacturers have located their lamps both inside and outside of the car, from the roof to the deck, and have equipped them with circular and rectangular lenses of varying sizes. Our standards are generally expressed in performance terms so that manufacturers have the freedom to design their vehicles in the manner most suited to them to meet the performance requirements, and so that a specification that appears to favor a proprietary device (e.g., mandating a specific design solution to a standard's requirements) is avoided.

Because of the latitude in design that Standard No. 108 affords, we do not regard the lamp as having any single inventor or designer. While it is possible that you have designed a lamp with some proprietary elements, your search for recovery is properly directed towards lamp and vehicle manufacturers. You have been ill-advised to seek recovery from the government, for you have no legal basis to do so.

ID: nht92-4.27

Open

DATE: August 21, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: S. Watanabe -- Manager, Automotive Equipment Legal and Homologation Sect., Stanley Electric Co. Ltd.

TITLE: None

ATTACHMT: Attached to letter dated 8/7/92 from S. Watanabe (signature by P.P. F. Nakayama) to Paul J. Rice

TEXT:

This responds to your letter of August 7, 1992, with respect to the legality under Federal Motor Vehicle Safety Standard No. 108 of two configurations of rear stop/taillamps and center highmounted stop lamps (CHMSL) on passenger cars.

In your Figure 1, the stop/taillamps are mounted at 72 inches height above the road surface, while the CHMSL is mounted 3 inches below the rear window. In your Figure 2, the stop/taillamps are again mounted at 72 inches while the CHMSL is mounted above the rear window and between the stop/taillamps. You believe that both Figures depict a conforming rear lighting scheme under Standard No. 108.

You are correct. Standard NO. 108 does not specify any spatial relationship between the CHMSL and stop lamps or taillamps. It permits the CHMSL to be mounted anywhere on the vertical centerline of the passenger car, but not lower than 3 inches below the rear window. Standard No. 108 also permits stop and taillamps to be mounted not higher than 72 inches above the road surface. Your two Figures do not exceed these regulatory parameters, and thus, each is permitted by Standard No. 108.

However, the research that proved the efficacy of the CHMSL in addressing the problem of rear end collisions was based upon a triangular configuration of stop lamps in which the CHMSL was the apex. We note that the CHMSL in Figure 1 is at the apex of an inverted triangle, while in Figure 2 the CHMSL is simply a lamp in a horizontal array. It is possible that the benefits of the CHMSL would not be realized through use of the configurations depicted in Figures 1 and 2, even if they are permitted by Standard No. 108.

ID: aiam3428

Open
Richard E. Jenkins, Esq., Assistant Patent Counsel, Burlington Industries, Inc., Greensboro, NC 27420; Richard E. Jenkins
Esq.
Assistant Patent Counsel
Burlington Industries
Inc.
Greensboro
NC 27420;

Dear Mr. Jenkins: This responds to your recent request for an interpretation of Federa Motor Vehicle Safety Standard No. 117 (49 CFR S 571.117). Specifically, you asked if the addition of 'edger fabric strips', pursuant to a process covered by U.S. Patent 4,196,764, would violate the prohibition in section S5.2.2(b) of Standard No. 117 against adding belts to retreaded passenger car tires.; The described process is prohibited by section S5,2.2(b) (sic), becaus it is clearly adding a belt to the tire.; In the abstract of the subject patent, which you included in you request for an interpretation, is the following statement: 'The invention relates to the use of reinforcing cords associated with the pneumatic tire . . ., and the method of applying such reinforcing cords woven in a warp and weft relationship cut in a bias shape to form a belt....' Similarly, in the *Detailed Description of the Preferred Embodiments* section of the patent, Section 3 begins, 'The essence of my invention is achieved by providing an extra belt....' Hence, the patent itself states that this process involves the addition of a belt to retread tires. Such an addition is expressly forbidden by section S5.2.2(b) of Standard 117, 'No retreaded tire shall be manufactured with a casing on which a belt or ply, or part thereof, is added or replaced during processing.'; Your letter stated that this edger fabric should not be considered belt for purposes of the Standard, because the addition of the edger makes a retreaded tire safer and longer lasting. While you may be correct concerning the performance of 'edger fabric,' the Standard as currently written does not permit its use. If you wish, however, you may file a petition for rulemaking requesting this agency to amend Standard 117 to permit the addition of a belt such as edger fabric by following the requirements set forth in 49 CFR Part 552 (copy enclosed). If you choose to do so, please include all data showing that the addition of this extra belt makes the retreaded tire safer, and that the edger fabric belt would be compatable (sic) with the existing cords of the casing that is used.; Finally, let me point out that Standard 117 applies only to retreade *passenger car* tires. There is no safety standard applicable to retreaded tires for vehicles other than passenger cars, and the use of this patented process on those tires would not violate any requirements of this agency.; Mr. Hugh Oates of my staff sends his regards. Sincerely, Frank Berndt, Chief Counsel

ID: aiam1679

Open
Mr. Kenneth Winiarski, Field Enterprises Education Corp., Merchandise Mart Plaza, Chicago, IL 60654; Mr. Kenneth Winiarski
Field Enterprises Education Corp.
Merchandise Mart Plaza
Chicago
IL 60654;

Dear Mr. Winiarski: Your letter of October 8, 1974, to Mr. Bobby Boaz has been forwarded t this office for reply. You appear to be interested in obtaining some general statements regarding the applicability of motor vehicle safety standards to different types of motor vehicles.; We attempt to apply each Federal motor vehicle safety standard to a wide a range of motor vehicles and motor vehicle equipment as is reasonable, practicable and appropriate. It is not entirely accurate, however, to say that the standards apply to the performance of equipment which vehicles are required to have. The standards are divided conceptually into three types: those which apply to new vehicles, those which apply to motor vehicle equipment (*e.g.* tires, child seats, etc.) and those which apply to both vehicles and equipment. In the case of a standard which applies to vehicles, the tests employed by the standard can take into account vehicle structure, weight, and design. In other words it is the method by which equipment is integrated into a vehicle that is important, rather than the performance of the equipment taken alone.; Standards which apply to vehicles specify the particular vehicle type to which they apply. Most early vehicle standards applied only to passenger cars. Since that time we have attempted to expand the applicability of some of these standards to other vehicle types. In each case, as I indicated above, a standard must be reasonable, practicable, and appropriate for the type of vehicle to which it is applied. In some cases, this is a matter of technology as you suggest. In others, however, the question may be one of safety need. For example, some standards do not apply to trailers (*e.g.*, Standard No. 302, 'Flammability of interior materials') or to equipment for use in trailers (No. 205, 'Glazing materials') because State laws prohibit people from riding in trailers. In this regard standards can also be directed at particular vehicle types to alleviate safety problems particular to them. A good example of this is Standard No. 217, 'Bus window retention and release.'; Your statements regarding seat belts and the applicability of Standard No. 208, 209, and 210 are not correct. While these requirements are somewhat complex, I believe an appropriate summary would be that seat belts and anchorages are required at all permanent seating positions including lateral or rearward positions, in all motor vehicles except trailers, motorcycles, and the passenger seats in buses.; Yours truly, Richard B. Dyson, Acting Chief Counsel

ID: aiam1678

Open
Mr. Kenneth Winiarski, Field Enterprises Education Corp., Merchandise Mart Plaza, Chicago, IL 60654; Mr. Kenneth Winiarski
Field Enterprises Education Corp.
Merchandise Mart Plaza
Chicago
IL 60654;

Dear Mr. Winiarski: Your letter of October 8, 1974, to Mr. Bobby Boaz has been forwarded t this office for reply. You appear to be interested in obtaining some general statements regarding the applicability of motor vehicle safety standards to different types of motor vehicles.; We attempt to apply each Federal motor vehicle safety standard to a wide a range of motor vehicles and motor vehicle equipment as is reasonable, practicable and appropriate. It is not entirely accurate, however, to say that the standards apply to the performance of equipment which vehicles are required to have. The standards are divided conceptually into three types: Those which apply to new vehicles, those which apply to motor vehicle equipment (*e.g.* tires, child seats, etc.) and those which apply to both vehicles and equipment. In the case of a standard which applies to vehicles, the tests employed by the standard can take into account vehicle structure, weight, and design. In other words it is the method by which equipment is integrated into a vehicle that is important, rather than the performance of the equipment taken alone.; Standards which apply to vehicles specify the particular vehicle type to which they apply. Most early vehicle standards applied only to passenger cars. Since that time we have attempted to expand the applicability of some of these standards to other vehicle types. In each case, as I indicated above, a standard must be reasonable, practicable, and appropriate for the type of vehicle to which it is applied. In some cases, this is a matter of technology as you suggest. In others, however, the question may be one of safety need. For example, some standards do not apply to trailers (*e.g.*, Standard No. 302, 'Flammability of interior materials') or to equipment for use in trailers (No. 205, 'Glazing materials') because State laws prohibit people from riding in trailers. In this regard standards can also be directed at particular vehicle types to alleviate safety problems particular to them. A good example of this is Standard No. 217, 'Bus window retention and release.'; Your statements regarding seat belts and the applicability of Standard No. 208, 209, and 210 are not correct. While these requirements are somewhat complex, I believe an appropriate summary would be that seat belts and anchorages are required at all permanent seating positions including lateral or rearward positions, in all motor vehicles except trailers, motorcycles, and the passenger seats in buses.; Yours truly, Richard B. Dyson, Acting 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.

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