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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 8951 - 8960 of 16517
Interpretations Date

ID: nht68-4.5

Open

DATE: 08/23/68

FROM: AUTHOR UNAVAILABLE; Charles A. Baker; NHTSA

TO: The Coleman Company, Incorporated

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of August 12, 1968, to Mr. Ed Laysath concerning lighting requirements on camper trailers.

The lamps and reflectors shown on your sketch appear to meet the requirements of Standard No. 108 with the exception that a license plate lamp is not indicated. Since no dimensions are specified on your sketch, we can only assume that the locations are as specified in the standard.

With respect to the requirements of Standard No. 103, I must point out that this Bureau does not issue approvals on items of lighting equipment or on vehicle designs incorporating this equipment. Therefore, the above comments are for your information only and in no way relieve the vehicle manufacturer from his responsibility for certifying that the assembled vehicle meets the requirements of Standard No. 108.

ID: nht68-4.6

Open

DATE: 08/27/68

FROM: AUTHOR UNAVAILABLE; H. M. Jacklin, Jr.; NHTSA

TO: Volkswagen of America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This will acknowledge your letter of July 31, 1968, to Mr. George C. Neild, Motor Vehicle Safety Performance Service, requesting the addition of a 5-K rim for use with a 5.60 x 15 tire to Table II of Federal Motor Vehicle Safety Standard No. 110.

On the basic of the data submitted showing satisfactory completion of the test requirements specified in the Federal Motor Vehicle Safety Standards No. 109 and No. 110, your request for the approved equivalent rim is granted.

The 5-K rim will be listed in Table II of Standard No, 110 and published in the Federal Register.

ID: nht68-4.7

Open

DATE: 09/02/68

FROM: AUTHOR UNAVAILABLE; C. D. Ferguson; NHTSA

TO: General Supply and Equipment Company, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of August 7, 1969, to the Federal Highway Administration, concerning head restraints on your 1969 Lincoln Continental Sedan.

Federal Motor Vehicle Safety Standard No. 202: Head Restraints Passenger Cars, specifies that a head restraint must be provided at each outboard front seating position on cars manufactured on or after January 1, 1969. This standard does not prohibit an individual from modifying or removing the head restraints once he purchases the car. However, a particular state may have inspection laws which prohibit such actions. I suggest you check the matter with your state inspection authorities.

Our Highway Safety Program Standards, copy enclosed, set minimum performance requirements for state inspection programs. Each state is free to establish its own program which meets or exceeds the Federal guidelines. The fact that our Federal Motor Vehicle Safety Standard requires head restraints to be installed on all new passenger cars is evidence of our belief in the level of safety provided by these devices in rear collisions. We would strongly endorse a state inspection program which supported this and our other standards. I am enclosing a booklet which describes all of our motor vehicle standards.

Regarding your particular case, we agree that good visibility is necessary for the safe operation of an automobile. However, properly designed head restraints should not significantly restrict visibility. The injury-reducing benefit far outweights the slight loss of visibility which may occur in certain passenger cars. See(Illegible Word) to the head restraint standard enclosed.

As a practical matter, I would not recommend removal of your head restricts. Aside from the level of rear collision protestion which they provide, their removal may mean that their support structure within the seat back is exposed and this may present a hazard to any rear seat occupants who may hit their heads on the front seat back in a forward collision.

I would suggests the alternative of an additional rear view mirror on the right side of your vehicle to provide increased rear visibility.

Your interest in our progress is appreciated.

ID: nht68-4.8

Open

DATE: 09/03/68

FROM: JOHN A. MCLAINE -- DEPT. OF LAW AND PUBLIC SAFETY, DIV. OF MOTOR VEHICLES, NEW JERSEY

TO: National Highway Safety Bureau

TITLE: FMVSS INTERPRETATION

TEXT: As requested, we are enclosing a copy of the letter we wrote to Mr. Paul L. Nine of the Chrysler Corporation after he sent us literature describing the Dodge "Super-Lite".

Since receiving our letter, Mr. Nine has told us that the "Super-Lite" does not conform to the SAE Standards.

SAE J582 states that the color of the light from a supplementary passing lamp must be white. The light from the "Super-Lite" is blue when the person looking at the light is in certain positions in front of the light. When a driver looks into his rear-view mirror and the vehicle behind is equipped with a "Super-Lite" the driver sees a blue light in his rear-view mirror.

New Jersey and many other States have regulations restricting the use of a blue light on the front of a motor vehicle to a motor vehicle operated by a volunteer fireman on his way to a fire, and for other emergency purposes.

SAE J582 also states that for greatest visibility, with reasonable limitations of glare to approaching drivers, the left edge of the stray light immediately to the left of the high intensity zone should be aimed at the vertical line through the lamp center, at 25 feet.

The "Super-Lite" does not meet this requirement because the left edge of the high intensity zone of the "Super-Lite" is aimed 5 1/4" to the left of the vertical line through the lamp center at 25 feet.

I suggested to Mr. Nine that if the color of the "Super-Lite" could be made to conform to the SAE Standard, perhaps we could aim the "Super-Lite" in New Jersey to conform to the SAE requirement. Mr. Nine said that this would not be satisfactory because it would destroy the purpose of "Super-Lite".

The Chrysler engineers also told me that they do not recommend that the "Super-Lite" be used on two-lane highways. I do not know how such a restriction could be enforced to insure maximum safety.

According to the literature, the "Super-Lite" was designed to bridge the gap between high and low beam lights. Our experience has shown that where traffic density permits the use of high beam lights there is no need for additional lighting and when traffic density requires the use of low beam lights there is no need for additional lighting because the tail lights and head lights of the vehicles ahead provide ample guidance.

In spite of the fact that "Super-Lite" does not meet the SAE Standards, Mr. Nine does not believe we can prohibit the use of this light in New Jersey because of Federal Law 89-563 which requires that no State shall have any safety standard applicable to the same item of equipment which is not identical to the Federal Standard.

As you know, Federal Standard 108 requires headlamps, tail lamps, stop lamps, license plate lamps, parking lamps, back-up lamps, turn signal lamps, side marker lamps, and reflectors in accordance with SAE Standards and recommended practices.

Section S 3.1.2 of Standard 108 states that no additional lamp, reflective device and associated equipment shall be installed if it impairs the effectiveness of the required equipment. Mr. Nine believes the Federal Government allows the "Super-Lite under the above section.

We do not believe the Federal Government should permit the use of a driving light which does not meet the SAE Standards, especially since all other motor vehicle lighting equipment is required to meet the SAE Standards. We also believe that the NHSB should have tests made to make certain that the use of auxiliary lights does not impair the effectiveness of the required equipment, and does not increase the danger caused by glare and confusion with various types of emergency lighting equipment.

Your comments will be appreciated.

ID: nht68-4.9

Open

DATE: 09/03/68

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

TO: Department of California Highway Patrol

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of August 19, 1968.

You state that you do not find any provision which would permit temporary mounting of lighting devices on mobile homes and ask that we inform you what provision in Public Law 89-563 or the Federal motor vehicle safety standards permits installation of temporary devices. There is no provision in P.L. 89-563 or the standards which either permits or prohibits the temporary mounting of devices. The National Highway Safety Bureau has taken the position that, insofar as mobile homes are concerned, temporary lighting devices may be used if they meet the requirements of Standard No. 108.

With respect to your request for a copy of Docket No. 26, I enclosed a copy of the notice of request for comments recently issued and published in the Federal Register. This docket was opened several months ago and contains several hundred pages of documents. The docket is scheduled to remain open, for the receipt of additional comments, until September 10, 1968. Our rules require us to charge 50 cents per page, payable in advance for copies of docket material. should you want a copy of the complete docket, please let us know and we will advise you, after September 10, of the fee for this service.

Thank you for your continuing interest in motor vehicle safety.

ID: nht69-1.1

Open

DATE: 01/27/69

FROM: AUTHOR UNAVAILABLE; H. M. Jacklin, Jr.; NHTSA

TO: American Honda Motor Company, Ltd.

TITLE: FMVSS INTERPRETATION

TEXT: This will acknowledge your letter of November 18, 1968, and your subsequent telephone conversation of December 4, 1968, with a member of the Tire Branch, requesting the addition to Federal Motor Vehicle Safety Standard No. 110 of the 3.50B alternative rim size for use with the 145-10 redial tire size designation.

On the basis of the data submitted indicating compliance with the requirements of Federal Motor Vehicle Safety Standards No. 109 and No. 110 and other information submitted in accordance with the procedural guidelines set forth in the Federal Register, Volume 33, No. 195, page 14969, dated October 5, 1968, the 3.503 alternative rim size for the 145-10 tire size designation will be listed within Table I of Appendix A to Standard No. 110.

The addition of this alternative rim size to the table in accomplished through an abbreviated procedure consisting of the publication in the Federal Register of the petitioned alternative rim size. If no comments are received, the amendment becomes effective 30 days after the date of publication. If comments objecting to amendments are received, additional rule making pursuant to Part 216 of the Procedural Rules for Motor Vehicle Safety Standards will be considered.

ID: nht69-1.10

Open

DATE: 12/28/69

FROM: AUTHOR UNAVAILABLE; Charles A. Baker; NHTSA

TO: Asplundh Chipper Company

TITLE: FMVSS INTERPRETATION

ID: nht69-1.11

Open

DATE: 01/27/69

FROM: AUTHOR UNAVAILABLE; Francis Armstrong; NHTSA

TO: THE NEW YORK AIR BRAKE COMPANY

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of September 30, 1968, regarding location of reflex reflectors and side marker income relative to trailer envelope dimensions. From your subsequent phone conversation on October 18, 1968, with Mr. Zolley of our office, I understodd that you are concerned about the possible obstruction of visibility of those devices by the trailer body.

Federal Motor Vehicle Safety Standard No. 168 specifies that side marker lamps must be in accordance with SAS Standard(Illegible Words) to end reflect reflectors in accordance with SAS Standard JS94c. These standards specify photo-metric requirements for side marker lamps at angle 45o to the right and left of the lamp vertical axis and for reflex reflectors at angles 20o to the right and left of the reflector vertical axis.

Although Standard No. 108 does not specify that these devices provide the test photometrics when installed on the vehicle, it should be noted that Tables II and IV of the standard do require that the devices be located "on the side" of the car vehicle. Therefore, devices that are recessed to an extent that would impair their effectiveness would not(Illegible Words) the requirements of Standard No.(Illegible Words).

Section S3.1.1.S of Federal Motor Vehicle Safety Standard No. 108, as amended effective January 1, 1989, specifics that for trailers less than 89 inches overall wide and less than 30 feet overall length, the photometric requirements specified in SAE J502, why be(Illegible Words) or inboard less points at a distance of 15 feet from the vehicle and on a vertical plane that is perpendicular to the longitudinal axis of the vehicle and located midway between the front and rear side marker lamps. For vehicles less than 20 feet in overall length, this establishes a point less than 45o on one side of the side marker lamps. This is the only sets of relief from the requirements of SAS J592b.

I trust this information will be helpful to you. If you should have my further questions concerning safety standards, I would be most happy to discuss them with you.

Sincerely,

September 30, 1968

Office of Motor Vehicle Performance Service National Highway Safety Bureau

Attention: Bruce A. Kelley --

Room 8213A Subject: Federal Motor Vehicle Safety

Standards - May, 1968

Dear Sir

In reply to my letter concerning an interpretation of the Federal Motor Vehicle Safety Standards, Mr. John A. Hanson, Regional Federal Highway Administrator suggested that I contact your office.

The point that I would appreciate clarification on is as follows:

1. Table IV, under Columns 2 and 4, for trailers less than 80" overall width clearly defines the location of the Reflex Reflectors and Side Marker Lamps as to vertical height above the road surface and that they appear on a horizontal level plane.

2. The question arises in determining the location of said lights in relation to the trailer envelope dimensions.

Mr. Kelley suggested that SAE Standards J594c and 592b are more specific and may answer my question.

Any comment you may have to clarify this situation would be greatly appreciated.

Very truly yours,

KINNEY VACUUM DIVISION,

The New York Air Brake Company --

D. F. Rusconi --

Project Engineer

ID: nht69-1.12

Open

DATE: 03/16/69

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

TO: Corporation Commission of Oaklahoma

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of April 15, 1969, in which you inquire about Federal regulation of brake fluid.

Brake fluid performance is regulated under the National Traffic and Motor Vehicle Safety Act by Federal Motor Vehicle Safety Standard No. 116. Copies of the Act and the current standards are enclosed.

Under the Vehicle Safety/Act, manufacturers of motor vehicles and equipment (including brake fluid) that are covered by standards are fully responsible for ensuring that all of their products conform to the standards. The National Highway Safety Bureau conducts conformity tests of vehicles and equipment, either through its own personnel and facilities or under contract with other public or private testing organizations, but these are for enforcement purposes only.

The Bureau is conducting a continuing series of tests on brake fluid, that has included samples from a majority of the major manufacturers, and will include the remainder is the near future. If you need more detailed information concerning this testing program, I suggest that you contact Mr. Francis Armstrong, Director, Office of Performance Analysis, National Highway Safety Bureau, Federal Highway Administration, Washington, D.C. 20591.

In answer to your Final question, Standard No. 116 applies to all brake fluid manufactured or sold in the United States, and is not Limited to that sold by automobile manufacturers or distributors.

ID: nht69-1.13

Open

DATE: 02/26/69

FROM: AUTHOR UNAVAILABLE; Clue D. Ferguson; NHTSA

TO: Mr. T. Sudderth

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of January 22, 1969, concerning safety glazing in your motor home.

We do not know what is meant by the description "Windows-Double Density - glass - set."

Glasing materials in a motor home must be in accordance with Federal Standard No. 205. Glass in the windshield must be AS1, not AS2 as your letter states. The windows on either side of the driver's compartment may be AS2, and AS2 may be used in the balance of the windows when needed for driver visibility or AS3 may be used in the balance of the windows when not needed for driver visibility.

The markings of glazing materials cited in your letter indicate that the materials used in your motor home are in accordance with Federal Standard No. 205, with the exception that you state that AS2 is marked on the windshield.

Please advise me if AS1 is not installed in the windshield of your motor home.

Sincerely,

January 22, 1969.

The National Highway Safety Bureau Department of Transportation

Gentlemen:

A few months ago I bought a new Dodge Motor Home (Travco) and it was ordered out from production with a number of option equipment items. One was identified as -

"Windows - Double Density - glass - Set

As of this date I am not too sure that this was included in the assembly and I have no way to identify the item and judge if I have paid a fair price.

Will you please assist me - The glass in the windshield and two side of driver compartment are marked as

Guardian Safety Glass As 2-67

Tempalite Solid Tint GG M 66

The glasses on the side walls are market's as follows - TWI-Lite Safety-Lite AS 3 M 21

The rear window is marked -

AT Asorbing Safety Glass

Solid Tempered M " 286

I am unable to see any identification on the two small glasses in the entrance doow assembly.

Your prompt comments will be appreciated.

Yours very truly

T. Sudderth

PO Box 757 - Laurens 29360

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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