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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 8261 - 8270 of 16517
Interpretations Date

ID: nht89-2.88

Open

TYPE: INTERPRETATION-NHTSA

DATE: 08/30/89

FROM: JOHN K. MOODY -- MOODY & MOODY ENTERPRISES

TO: TAYLOR VINSON -- LEGAL COUNSEL NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION FMVSS-108 U.S. DEPARTMENT OF TRANSPORTATION

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 11/01/89 FROM STEPHEN P. WOOD -- NHTSA TO JOHN K. MOODY -- MOODY AND MOODY ENTERPRISES; REDBOOK A34; STANDARD 108; LETTER DATED 09/14/89 FROM S. WATANABE -- STANLEY ELECTRIC COMPANY TO STEPHEN P. WOOD NHTSA; OCC 3931

TEXT: Dear Mr. Vinson,

My company is planning to market nationwide a vehicle aftermarket kit which effects the front turn signals on motor vehicles. The intent of this letter is to inquire as to whether or not vehicles equipped with our product would be in conflict with exist ing vehicle lighting standards established by N.H.T.S.A..

Prior to writing this letter I had telephone conversations with several individuals there at N.H.T.S.A. and the consensus was that, since our product does not interfere with the normal operation of the existing vehicle lighting equipment, there would be no conflict. It was recommended, however, that I write this letter to you in order to obtain an official evaluation of our product and to receive a reply in writing.

Our product is really quite simple. We connect both front turn signal lamp filaments so that when the brake pedal is pushed and the rear brake lights are illuminated, both front turn signal lights are also illuminated. If a turn signal is activated eit her before or during application of the brakes, the front turn signal light flashes in its normal manner thereby indicating the direction of turn while the other front turn signal light will be illuminated as long as the brake pedal is being pushed.

This product is intended to add a significant measure of safety to vehicles by providing a forward indication as to whether or not the driver of the vehicle is attempting to apply the brakes. This would be a benefit to other drivers and pedestrians alik e.

According to the directional analysis of 1987 motor vehicle traffic accidents published by the National Safety Council, this safety improvement could have been helpful in reducing 41.6% of all two car accidents (8,652,800) and 29.5% of all two car fatali ties (12774). In addition, we believe that a significant number of pedestrian-car accidents (90,000 total resulting in 8200 fatalities in 1987) could have been avoided had the car been equipped with a forward directed brake application indicator.

Although we are requesting your evaluation concerning our product's compatibility with vehicle lighting standards, we also would appreciate any comments which you or others would offer concerning your opinion as to the safety benefits which would result from vehicles being equipped with a forward directed brake application indicator.

For your information, we are sending a similar letter to each state requesting their opinion concerning our product and their state vehicle lighting regulations.

Thank you for your attention to this matter. A prompt reply would be greatly appreciated.

Sincerely,

ID: nht89-2.89

Open

TYPE: INTERPRETATION-NHTSA

DATE: 08/31/89

FROM: STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL

TO: MARK RECCHIA -- FIAT RESEARCH AND DEVELOPMENT U.S.A. BRANCH

TITLE: NONE

TEXT: Dear Mr. Recchia:

This responds to your telephone call asking about an apparent inconsistency between the requirements of S4.1 of Standard No. 302, Flammability of Interior Materials, and NHTSA's laboratory procedures for flammability compliance tests (June 1973). You as k whether the laboratory procedures are correct in specifying that all materials found in the vehicle occupant compartment must meet the flammability resistance requirements of the standard. I regret the delay in responding. The answer is no.

Paragraph S4.1 of Standard No. 302 sets forth a listing of the components of vehicle occupant compartments that must be certified as complying with the flammability resistance requirements of paragraph S4.3. Paragraph S4.1 includes a reference to "any o ther interior materials . . . that are designed to absorb energy on contact by occupants in the event of a crash." That paragraph represents a complete listing of all components in new vehicles that must comply with the flammability resistance requiremen ts. Any component not identified in paragraph S4.1 is not subject to those requirements.

Paragraph 10.1 of NHTSA's laboratory procedures also lists the components of vehicle occupant compartments that must meet Standard No. 302. That listing was intended to include only the components described in S4.1 of the standard, but inadvertently mak es a general reference to "[a]ny other materials" in the vehicle interior compartment (item number 19) without including the modifying clause, "that are designed to absorb energy on contact by occupants in the event of a crash." The modifying clause shou ld have been included, since Standard No. 302 applies only to the vehicle components identified in S4.1 of the standard.

Sincerely,

ID: nht89-2.9

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/19/89

FROM: STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL

TO: H. HASEGAWA -- AUTOMOTIVE LIGHTING ENGINEERING CONTROL SECTION STANLEY ELECTRIC CO. LTD.

TITLE: NONE

ATTACHMT: LETTER DATED 05/22/89 FROM H. HASEGAWA TO RICHARD L. VANIDERSTINE, RE REVISION OF FMVSS NO 108 [DOCKET NO 85-15 NOTICE 8

TEXT: Dear Mr. Hasegawa:

This is in reply to your FAX letter of May 22, 1989, to Richard Van Iderstine of this agency.

You have two questions with respect to the amendment to Standard No. 108 published on May 9, 1989 (Docket No. 85-15; Notice 8).

Your first question is the effective date of paragraph S7.7.5.1.(a), which you point out was not previously a requirement of Standard No. 108. You suggest the need for a delayed effective date (but give no reason why one may be needed).

Paragraph S7.7.5.1(a) will be effective June 8, 1989. Although the requirement is a new one (the restriction on motion of a headlamp when an external aiming device is applied to it), it was proposed as part of the December 29, 1987 NPRM, and no comments received indicated a need for a delayed effective date. Your supposition is correct; S7.5.5.1 will apply to all headlamps with an external aiming system, including those incorporating replaceable bulbs.

Your second question relates to paragraph S7.7.5.1(b), and you ask "whether the requirement of '0.1 in. max.' will be determined, either during the test or after the test". In pertinent part, subsection (b) states "nor shall the lamp recede more than 0. 1 in. (2.5 mm) after being subjected to an inward force...." This means that the measurement is determined after the test.

Sincerely,

ID: nht89-2.90

Open

TYPE: INTERPRETATION-NHTSA

DATE: 08/31/89

FROM: STEPHEN P. WOOD -- NHTSA ACTING CHIEF COUNSEL

TO: BRADLEY J. BAKER -- PRESIDENT CLASSIC MANUFACTURING, INC.

TITLE: NONE

ATTACHMT: LETTER DATED 10/21/88 FROM BRADLEY J. BAKER -- CLASSIC MANUFACTURING TO TAYLOR VINSON -- NHTSA; OCC 2717

TEXT: Dear Mr. Baker:

This is in reply to your letter to Taylor Vinson of this Office, with reference to a product your company manufactures, a "car dolly used to tow a vehicle behind motor homes." You question whether the dolly is a motor vehicle, and if so, whether identifi cation lamps are necessary for it. I regret the delay in responding.

The car dolly appears to be a vehicle drawn by mechanical power manufactured primarily for use on the public roads, and thus a "motor vehicle" subject to the jurisdiction of this agency. Specifically, it would be a "trailer", since it is a motor vehicle without motive power, designed for carrying property and for being drawn by another motor vehicle. Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective Devices, and Associated Equipment, requires identification lamps on all trailers whose o verall width is 80 inches or more. Therefore, if the overall width of your dolly is less than 80 inches, it need not be equipped with identification lamps.

Sincerely,

ID: nht89-2.91

Open

TYPE: INTERPRETATION-NHTSA

DATE: AUGUST 31, 1989

FROM: J. BRETTSCHNEIDER -- ROBERT BOSCH GMBH

TO: RICHARD VAN IDERSTINE -- DOCKET SECTION, NHTSA

TITLE: PERFORMANCE OF THE IMPACT TEST ACCORDING SAE J1383

ATTACHMT: ATTACHED TO LETTER DATED 3-29-90 TO J. BRETTSCHNEIDER, ROBERT BOSCH GMBH, FROM STEPHEN P. WOOD, NHTSA.

TEXT:

According to the above-mentioned SAE Standard (recommended practice), Section 4.10.3, the impact test has to be performed ... along the mechanical axis ...

SAE Standard J 579, Section 2.14 defines the mechanical axis as ... perpendicular to the aiming plane through the geometric center of the lens.

Now the questions arise

- where is the geometric center of a lens without aiming pads?

- where is the geometric center of a lens which moreover covers two compartments, one for the lower beam and one for the upper beam?

Please give us your advice.

Thanking you in advance.

ID: nht89-2.92

Open

TYPE: INTERPRETATION-NHTSA

DATE: AUGUST 31, 1989

FROM: CADWALLADER JONES -- PRESIDENT, JONES FORD INC.

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 3-20-90 TO CADWALLADER JONES, JONES FORD INC., FROM STEPHEN P. WOOD, NHTSA; [A35; VSA 102(14); PART 571.3]

TEXT: We need some help in the interpretation of Section 571.3 of Title 49 of the Code of Federal Regulations. This involves the sale, lease or rental of Ford Motor Company manufactured Econoline Vans and Club Wagons. We understand that these vehicles having more than 10 designated seating positions are not intended for use as "school buses" and are not designed to comply with certain Federal Motor vehicle safety standards uniquely applicable to school buses. We understand that a school bus is defined in S ection 571.3 as a "Motorvehicle -- designed for carrying more than 10 persons -- that is sold, or introduced into interstate commerce, for purposes that include carrying students to and from school or related events, but does not include a bus designed a nd sold for operation as a common carrier in urban transportation."

We have questions of further definition of "school bus" and of "student".

1. Is there an age limit or occupational definition of "student"?

A) Adults being transported to and from adult education classes by United Way.

B) College students-athletic teams, etc.

C) Churches that don't have day schools but transport children on occasions

D) Highschool students-athletic teams, etc.

E) Playground teams-no connection with schools

F) Day care center

We understand the prohibition against installing smaller size seats in a window van and painting it school bus yellow like we used to do in the '70s. It's these "fringe" uses that are not on a daily basis about which we are concerned.

We will appreciate your help in this area.

ID: nht89-2.93

Open

TYPE: Interpretation-NHTSA

DATE: September 1, 1989

FROM: Louis F. Wilson -- Instant Traffic Lights

TO: NHTSA, Department of Transportation

TITLE: Re Vehicle Signalling System

ATTACHMT: Attached to letter dated 3-8-91 from Paul Jackson Rice to Louis F. Wilson (A37; Std. 108); Also attached to letter dated 2-20-91 from Louis F. Wilson to NHTSA (OCC 5747); Also attached to letter dated 2-20-90 from Louis F. Wilson to NHTSA

TEXT:

As you know, an automobile is a necessity for most Americans. The automobiles on the road today comes equipped with indicator lights installed for safety, yet the number of accidents still seem quite numerous. We feel that our product, Instant Traffic Lights, will most likely make the road safer for all motorists.

How can we make that claim? If our product is installed on all auto- mobiles on the road, it will let the motorist behind know the intentions of the driver ahead. Whether the driver ahead is applying his accelerator or brake pedals or just coasting, th e motorist behind would know the exact intentions of the driver ahead. Benefits of knowing the intentions of the driver ahead are quite numerous. Some of the benefits are: it will probably reduce tail gating, sudden stops, skidding, and rear end collis ions.

Since every second counts on the road, we feel that our product will increase the safety factor for all motorists and perhaps for pedestrians as well. Like we said before, our product will let the motorist behind know the exact intentions of the driver ahead, perhaps a half a second or more sooner than the conventional lighting system on the automobiles on the road today. At 60 MPH, an automobile travels 88 feet per second. That half a second or more, which would be gained by having our product instal led, will give the motorist behind an excess of 44 feet more than the conventional lighting system to stop or to avoid the hazard.

On top of all that, our product would probably save wear and tear in the brakes and tires and most importantly, will save fuel in the long run, if, all motorists have our product installed onto their cars. All these claims that we are making have not be en tested on the road as of yet, but anyone with common sense can see that our claims are quite valid.

Our product would be used mainly for safety purposes only, but it also serves as an economical one as well.

So far, we have sent letters to all fifty states and to the Secretary of Transportation inquiring, "whether our product is legal in their state as of now." Sixteen states have answered our letter, of which, six states said, "yes", six states said, "no", and four states said that they will follow the Federal requirements.

What we would like to know is: 1) Would our product meet the standard of your office? 2) Would our product be "legal" in the United States and her territories? 3) Is it possible to replace (or provide an option to) the existing high-mounted stop light required on passenger cars manufactured on or after September 1, 1985 (Per Federal Motor Vehicles Safety Standard #108)? Please review the attached copy of our U.S. patent application and make necessary recommendations and/or comments. We would apprec iated if you would take a little bit of your time to reply these questions and send them back to us as soon as possible. Thank You.

ID: nht88-2.80

Open

TYPE: INTERPRETATION-NHTSA

DATE: 08/01/88 EST

FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA

TO: C. DIANNE BLACK -- ENGINEERING MANAGER, JAGUAR CARS, INC.

TITLE: NONE

ATTACHMT: MEMO DATED 4-14-88, TO ERIKA Z. JONES, FROM C. DIANNE BLACK -- JAGUAR, REF: FMVSS 108, HEADLAMP LEVELLING SYSTEM

TEXT: Thank you for your letter of April 14, 1988, providing further information about the Jaguar headlamp levelling system discussed in your letters of June and October 1987 to which I responded on February 1, 1988.

We support your efforts to call the driver's attention to the fact that the system does not automatically return to the "zero" position from either of the two adjustment positions when those loading conditions no longer exist.

ID: nht88-2.81

Open

TYPE: INTERPRETATION-NHTSA

DATE: 08/01/88 EST

FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA

TO: ROBERT G. YORKS -- VICE PRESIDENT AND GENERAL MANAGER, AUTOMOTIVE BUSINESS GROUP, TRUCK-LITTLE CO.

TITLE: NONE

ATTACHMT: MEMO DATED 5-24-88, TO KATHLEEN DEMETER, FROM ROBERT G. YORKS, 25220; MEMO UNDATED, TO ROBERT G. YORKS, FROM KATHLEEN DEMETER

TEXT: We have received your letter of May 24, 1988, withdrawing your request for confidential treatment of your letter of March 31 concerning the legality of a new safety lighting device. This letter also responds to your inquiry of July 14.

The device is described as a "combination center high-mounted stop lamp and cargo lamp". The functions are optically separate. The cargo lamp can illuminate the cargo box on pick-up trucks, while on vans and utility vehicles it serves as a "utility lig ht". The device is intended to be used as either original or aftermarket equipment.

The Federal motor vehicle safety standard on vehicle lighting is Standard No. 108. As you know, the center high-mounted stop lamp is required only for passenger cars. Further, there is no requirement that a center lamp intended for other types of motor vehicles meet the passenger car lamp requirements (for example, those requirements would prohibit combining the center lamp with the cargo lamp). As neither function of your device is required on lighting equipment for vehicles other than passenger car s, Standard No. 108 permits the installation of your device as original equipment provided that it does not impair the effectiveness of the lighting equipment that the standard does require. Whether impairment exists is initially a determination of the manufacturer of the vehicle who certifies compliance with Standard No. 108. However, the issue of impairment is ultimately subject to a determination by this agency. Types of impairment that can exist include functional interference with the wiring of o ther lamps, creation of ambiguous or confusing signals to such a degree that it may obscure the message of lamps and reflectors required by Standard No. 108, and reduction of photometrics below the minimum levels specified.

As an item of aftermarket lighting equipment, it is subject to a restriction of the National Traffic and Motor Vehicle Safety Act that its installation by a manufacturer, dealer, distributor, or motor vehicle repair business must not render inoperative i n whole or in part any device or element of design installed in accordance with a Federal motor

vehicle safety standard. We construe this prohibition strictly and equate it with impairment. If performance is "impaired," it can be viewed as "inoperative" with respect to achieving the purpose for which it has been installed.

Assuming that installation of an aftermarket device is not restricted by the Act, it nevertheless remains subject to the laws of a State in which the vehicle is registered and driven. We are not conversant with State laws on combination rear lamps, but you may wish to consult the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203, for an opinion.

I hope that this answers your questions.

ID: nht88-2.82

Open

TYPE: INTERPRETATION-NHTSA

DATE: 08/01/88

FROM: WILLIAM E. LAWLER -- SPECIFICATIONS MANAGER INDIANA MILLS AND MANUFACTURING INC

TO: ERICA Z. JONES, -- CHIEF COUNSEL NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 11/01/88 EST TO WILLIAM E. LAWLER FROM ERIKA Z. JONES, REDBOOK A32, STANDARD 208, STANDARD 209

TEXT: Dear Chief Counsel:

The publication of the final rule (53FR25337) pertaining to seat belts in trucks, buses, and multipurpose passenger vehicles over 10,000 pounds GVWR (FMVSS 208) on July 5, 1988, has prompted us to write to you.

Our discussions with engineers in the Crashworthiness Division since August 1985 have centered around our product called the "Komfort-Lok." This patented device has been used in the field for over two years with good customer satisfaction. Unlike the wor ding of the recent final rule, the Komfort-Lok is not a retractor but rather a mechanism external to the retractor itself but integral with the retractor but which eliminates webbing movement and thus eliminates cinching. The Komfort-Lok works in conjunc tion with an automatic locking retractor (ALR) regardless of the amount of webbing retracted between locking points at 75 percent webbing extension.

Because the Komfort-Lok is designed to work effectively with any ALR, we are writing to your office to request an official opinion permitting the use of any FMVSS 209-compliant-ALR in conjunction with the Indiana Mills Komfort-Lok as a complete retractor system to satisfy the requirements of FMVSS 208, Paragraphs S4.3.2.2 and S4.4.2.2 as stated in the 7-5-88 final rule.

We appreciate your attention to our request.

If you have any questions, please contact me. Thank you.

Sincerely,

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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