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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 14391 - 14400 of 16490
Interpretations Date

ID: nht95-2.67

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 3, 1995

FROM: Doug Russell -- Design Engineer, Advance Engineered Products

TO: John Womack -- Acting Chief Counsel, NHTSA

TITLE: FMVSS 121 Paragraph S5.4.2.2 Brake Power

ATTACHMT: ATTACHED TO 06/29/95 LETTER FROM JOHN WOMACK TO DOUG RUSSELL (A43; STD. 121)

TEXT: Dear Sir

Recently, I have been reviewing test data used to certify brake components to FMVSS - 121. Could you please answer two questions which arose as a result of this review:

1. Paragraph S5.4.2.2. of FMVSS - 121 requires that a deceleration be made from 20 mi/hr to a stop at an average rate of 14 ft/s<2>. A maximum service line brake pressure is not specified for this deceleration. Thus, in order to meet the deceleration requirement, a service line pressure exceeding 100 lbs/in<2> could be used despite the fact that tractor - trailer brakes are usually configured to operate at a maximum nominal brake pressure of 100 psi. Are there any limitations on the pressure which c an be used to achieve the required deceleration rates?

2. Test results from one of Advance's suppliers show that the actual deceleration rate was approximately 15% below the 14 ft/s<2> specified in paragraph S5.4.2.2. I have discussed these results with NHTSA's Richard Carter, and according to him the mini mum requirements of FMVSS-121 have not been met. However, according to the supplier, this stop must be done as part of the whole dynamometer test procedure but not meeting the deceleration requirements for this particular stop does not constitute a fall. Have any interpretations been made which allow a reduced deceleration rate?

Please call if you have any questions. Thank-you

ID: nht90-3.91

Open

TYPE: Interpretation-NHTSA

DATE: September 10, 1990

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Kent D. Smith

TITLE: None

ATTACHMT: Attached to letter dated 4-27-90 from K.D. Smith to S.P. Wood (OCC 4761)

TEXT:

This is in reply to your letter of April 27, 1990, to Stephen P. Wood of this Office, as a follow-up to his letter of March 22 replying to your request for an interpretation on January 26.

Your device activates the backup lamps for a period of one second or less as a signal to the driver of a following car that (s)he should lower the headlamp beam. Mr. Wood informed you that use of backup lamps for any other than their intended purpose co uld be viewed as an impairment of the backup signal function, and would thereby be prohibited under Federal Motor Vehicle Safety Standard No. 108. You now ask two further questions.

The first question is "What steps would have to be taken in regard to (SAE Standard J593e, Backup Lamps) which would permit me to test market this product?" You have cited paragraph 4.2 which states that "Backup lamps shall not be lighted when the vehic le is in forward motion." As a minor correction, let me note that the SAE Standard incorporated by reference in Standard No. 108 is J593c, February 1968, and the paragraph cited appears with the identical wording as paragraph 2 under "Installation Requi rements." We have no specific authority under which an inventor can install a device on motor vehicles in use for test marketing purposes when the installation might result in a noncompliance. In fact, the National Traffic and Motor Vehicle Safety Act specifically prohibits a manufacturer, distributor, dealer, or motor vehicle repair business from rendering inoperative, in whole or in part, any device or element of design installed on a vehicle pursuant to a Federal safety standard. Because the instal lation would result in a noncompliance by operation of the backup lamps while the vehicle was in forward motion, its installation for test market purposes on vehicles in use appears precluded by the statutory prohibition.

However, a manufacturer of motor vehicles may petition for a temporary exemption from paragraph 2 on the basis that an exemption would facilitate the development and field evaluation of an innovative safety device. Such exemptions may be granted for a p eriod of up to two years, and they cover up to 2500 vehicles a year while the exemption is in effect. I enclose a copy of 49 CFR Part 555 which contains our exemption procedures. Thus, to test market your device you would have to persuade a manufacture r of new motor vehicles to petition for its use.

Your second question is whether you would be in violation of Federal law by manufacturing and selling this device. The answer is no. This device is outside the coverage of Standard No. 108, and no one is prohibited from either selling the device or buy ing it. However, as noted earlier, its installation by a manufacturer, distributor, dealer, or motor vehicle

repair business on a vehicle in use, would be prohibited by the Act.

Attached is a copy of 49 CFR Pt 555 (text omitted).

ID: nht74-4.37

Open

DATE: 01/08/74

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: American Retreader's Association, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of November 20, 1973, asking under what conditions retreaded tires, which you describe as, "not first class mainly from the standpoint of appearance, may be sold. You state that the tires are not defective, and are being sold for non-highway use, such as for farm wagons and hay bailers.

Standard No. 117 (Retreaded pneumatic tires) applies to all retreaded tires manufactured for use on passenger cars. The sale of such tires for off-highway vehicular purposes does not remove them from the coverage of the standard. Consequently, the tires must comply fully with Standard No. 117, bear the manufacturer's identification number (49 CFR Part 574), and not be restricted to off-road operation.

November 20, 1973

Mike Peskoe Assistant Chief Counsel National Highway Traffic Safety Administration

A number of our members have written, asking us questions concerning the sale or disposition of retreads that are not first class, mainly from the standpoint of appearance. They are not defective.

(Illegible Word) retreads are being sold to implement dealers for non-highway(Illegible Word) such as on farmwagons, hay balers, etc.

1.) Should the retreader remove his assigned identification mark before selling it?

2.) Should he leave his assigned identification mark on the retread and brand or otherwise permanently identify it as being for farm or non-highway use?

3.) Should he remove his assigned identification mark and permanently identify it as being for farm or non-highway use?

Your help in clarifying these questions will be appreciated.

Arden H. Faris Assistant Director

ID: nht90-2.33

Open

TYPE: Interpretation-NHTSA

DATE: April 26, 1990

FROM: Stephen P. Wood -- Acting Chief Counsel., NHTSA

TO: Joan E. Fogelman -- Lund & Pollara, Inc.

TITLE: None

ATTACHMT: Attached to letter dated 4-2-90 To Taylor Vinson and From Stephen P. Wood; (OCC 4602)

TEXT:

This is in reply to your FAX of April 2, 1990, to Taylor vinson of this Office, with reference to a 1985 Mercedes-Benz 280SE sedan being imported from the Bahamas temporarily, for the purpose of repair. You have stated that "U.S. Customs wants a reassura nce that they will not be held accountable if for some unforseen happening, this vehicle is not properly exported."

Although the new DOT vehicle importation regulations effective January 31, 1990, make no specific provision for temporary importation of a nonconforming motor vehicle for repairs, when such a vehicle is owned by a nonresident of the United States and reg istered in a country other than the U.S., it is acceptable to this agency for the nonresident owner to enter it under the provisions of 49 CFR 591.5(d), the declaration by an importer who provides his passport number and country of issue that he is a non resident importing the vehicle for personal use for a period not to exceed one year and will not sell the vehicle during that time. Such an entry is not accompanied by the new DOT conformance bond, which is required only for entries pursuant to 591.5(f) and (g).

I do not know what Customs means by being held "accountable" if the vehicle is not properly exported. You have stated that it will be accompanied by a Customs bond, and I assume that if the terms of that bond are violated Customs will take whatever enfor cement action against the vehicle and its owner is deemed appropriate under the bond.

ID: nht73-1.30

Open

DATE: 10/25/73

FROM: E. T. Driver; NHTSA

TO: Marchal America

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your letter #8495, dated October 5, 1973 to the National Highway Traffic Safety Administration concerning the legality of an automotive headlamp having a sealed metal reflector, glass lens arrangement. It is understood from your letter that such a headlamp would meet all requirements of Federal Motor Vehicle Safety Standard No. 108, including photometric and electrical performance, interchangeability and mechanical aiming.

Specifically your question is: "Would a hermetically sealed metal and glass headlamp, (one in every way interchangeable with existing approved sealed beams except that the reflector would be metal instead of glass), be acceptable under current federal regulations?"

The answer to your question is "yes".

ID: nht74-4.2

Open

DATE: 06/06/74

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Earl E. Eckert

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of May 3, 1974, inquiring as to the applicability of the Federal odometer law to trucks over 16,000 pounds.

The Federal odometer regulation does not require transferors of vehicles with a Gross Vehicle Weight Rating of more than 16,000 pounds to provide an odometer disclosure statement upon transfer of the vehicle. By Gross Vehicle Weight Rating, the regulation is referring to the value specified by the manufacturer as the loaded weight of a single vehicle, which appears on its permanent certification label.

I have enclosed copies of pertinent portions of the Act and the regulation for your information.

ENCLS.

ID: nht90-3.25

Open

TYPE: Interpretation-NHTSA

DATE: July 19, 1990

FROM: Robert B. Roden -- Roden & Hayes

TO: Paul Jackson Rice -- Chief Counsel, NHTSA

TITLE: Re 15 USCS Section 1403

ATTACHMT: Attached to letter dated 6-3-77 from J.J. Levin, Jr. to L.J. Strobel (VSA 114); Also attached to letter dated 12-3-90 from P.J. Rice to R.B. Roden (A36; Std. 205)

TEXT:

I am writing to request your opinion regarding 15 USCS Section 1403. I am specifically interested in your opinion regarding whether the federal law requires some form of certification on every replacement item of motor vehicle equipment. It appears fro m the statutory language that such is the case.

We appreciate your opinions with respect to this matter.

ID: nht73-3.7

Open

DATE: 01/03/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Messrs. Carter and Carter

TITLE: FMVSR INTERPRETATION

TEXT: This is reply to your letter of December 14, 1972, to the Federal Highway Administration on behalf of your client, a snow plow dealer. You ask for verification "that the addition of a snow plow to a completed truck is considered the addition of a readily attached component and does not require recertification."

We confirm that a person adding a snow plow to a completed truck is not a final-stage manufacturer who is required by 49 CFR Part 568 to certify compliance of the vehicle with Federal motor vehicle safety standards. He is, however, responsible for insuring that the modified vehicle complies with Standard No. 108 before delivering it to its purchaser.

ID: nht94-2.69

Open

TYPE: INTERPRETATION-NHTSA

DATE: May 5, 1994

FROM: J. L. Steffy -- Triumph Designs Ltd.

TO: Taylor Vinson -- Office of Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached To Letter Dated 5/31/94 From John Womack To J.L. Steffy (A42; Std. 108)

TEXT: Dear Taylor

An additional concern for another unit with respect to FMVSS 108:

This is a self contained seal unit that would allow for symetric design & lighting. It comprises a headlight with high and low beams and 2 symetrically flanking front auxillary lamps possessing low beam that augment the headlight. Can you please comment on this as it affects our immediately plans for U.S. importation.

Thank you for your assistance

ID: GF007210

Open

    Mr. Jeff Oldham
    Performance Tires, LLC
    22810 Pennyrile Lane
    Katy, TX 77450

    Dear Mr. Oldham:

    This responds to your e-mail and previous phone conversation with George Feygin of my staff regarding the legality of "knock off" style wheel hubs. You intend to supply these wheel hubs to Factory Five Racing, a kit car manufacturer, who will in turn, sell unassembled kits to consumers. You ask whether "knock off" style wheel hubs satisfy the requirements of the Federal Motor Vehicle Safety Standards (FMVSS).

    In your e-mail, you describe the wheel hubs in question as follows: "An adapter goes over the existing studs which the wheel would typically mount to. The adapter is held on by lugs, then the wheel is slid over the adapter. The wheel itself is held on by an "knock off" style hub, which screws down onto the adapter on the face of the wheel. The knockoff screws on in a counter clockwise rotation (opposite direction of the wheels when the car is in drive)."

    By way of background, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under 49 U.S.C. Chapter 301, manufacturers are required to certify that their vehicles and equipment meet applicable requirements.

    There is no Federal Motor Vehicle Safety Standard regulating "knock off" wheel hubs. Previously, FMVSS No. 211 (Standard No. 211), Wheel nuts, wheel discs, and hub caps (49 CFR Section 571.211), precluded certain wheel nuts, wheel hubs, wheel discs, and hub caps from having "winged projections." We were concerned that the winged projections could catch on clothing or strike legs or other body parts, posing a hazard to pedestrians and cyclists. However, Standard No. 211 was rescinded as of June 5, 1996. [1]

    We note that despite the fact that NHTSA does not directly regulate wheel hubs, any wheel hub designed to be used on a motor vehicle is an item of "motor vehicle equipment" and is subject the recall and remedy provisions of Chapter 310. If a manufacturer or NHTSA determines that the product contains a safety-related defect, the manufacturer is responsible for notifying purchasers of the defective vehicle or item of motor vehicle equipment and remedying the problem free of charge.

    I hope this information is helpful. If you need further assistance, please contact George Feygin of my staff at this address or at (202) 366-2992.

    Sincerely,

    Jacqueline Glassman
    Chief Counsel

    Enclosure
    ref:211
    d.11/17/03




    [1] See 61 FR 20172, copy attached.

2003

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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