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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 13661 - 13670 of 16490
Interpretations Date

ID: nht92-6.1

Open

DATE: June 22, 1992

FROM: Eugene J. Welker

TO: Jackson Rice -- Chief Counsel, N.C.C.I., NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 8/7/92 from Kenneth N. Weinstein (for Paul J. Rice) to Eugene Welker (A39; Redbook (4); Std. 211; Std. 111)

TEXT:

Mr. Stronbotne suggested I write you relative to a mirror safety item that can be located near rear bumper on cars, trucks, vans, etc., to improve a driver backing out of either a perpendicular, 45 degree angle or other parking areas to ascertain if the way is clear for driver to proceed without endangering anyone.

The purpose of this letter is to question the legality of mirrors on rear of vehicles facing forward about 45 degrees so no following vehicles are affected by any reflection.

Mirrors on cars would be hinged on a vertical post and be a few inches above top rear window stop light. The two car mirrors are approximately 90 degrees apart or 45 degrees on each side so driver can tell from windshield if any traffic is coming from either direction prior to backing out.

Mirrors on prototype unit are 4" x 6" long, or approximately the size of mirrors on car doors. These are cut from 1/4" thick plexiglass and bolted on one end to hinge on vertical post.

Mirrors would be high enough on trucks, probably about heighth of ones outside drivers doors so driver can get a good view if all is clear before backing up.

I have made a prototype and can readily mount it on rear of my car above rear bumper in a few seconds with two small wing nuts to hold vertical shaft, approximately 35" long. I carry unit in car trunk so I can readily attach it if my vision is blocked on either side in rear.

In 1942 and 1943 I had the pleasure of working for the Small Arms Branch in the Pentagon expediting a variety of machinery and equipment.

Thank you for your assistance in this matter.

ID: 7638

Open

Mr. R.J. Misorski
Director, Maintenance & Repair
Maersk Inc.
231 Tyler Street
Port Newark, NJ 07114

Dear Mr. Misorski:

This responds to your letter of August 6, 1992, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108.

You write with reference to an amendment that became effective December 1, 1991, requiring a minimum of 12 square inches of lens area for rear stop or turn signals on vehicles over 80 inches wide, regardless of the separation between lamps. You request confirmation of your feeling that "equipment manufactured prior to December 1, 1991 would be exempt from this ruling", and that "it only applies to equipment that is manufactured after December 1, 1991." You have asked for this interpretation to "ensure compliance with our equipment fleet."

What the amendments require is that multipurpose passenger vehicles, buses, trucks, and trailers whose overall width is 80 inches or more, which are manufactured on and after December 1, 1991, be equipped with stop and turn signal lamps that meet the new requirements. Stop and turn signal lamps which were manufactured prior to that date that do not meet the new requirements are permissible to replace original equipment of the same type on vehicles manufactured before December 1, 1991, but they cannot be used as either original or replacement stop and turn signal lamps on vehicles manufactured on and after December 1, 1991. Furthermore, Standard No. 108 continues to allow manufacture and sale on and after December 1, 1991, of the old type of stop and turn signal lamps for replacement of original equipment on vehicles manufactured prior to December 1, 1991.

I hope that this assists you with your compliance question. We shall be pleased to answer any further questions you may have.

Sincerely,

Paul Jackson Rice Chief Counsel

ref:108 d:8/21/92

1992

ID: nht92-4.28

Open

DATE: August 21, 1992

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: R.J. Misorski -- Director, Maintenance & Repair, Maersk Inc.

TITLE: None

ATTACHMT: Attached to letter dated 8/6/92 from R.J. Misorski to NHTSA Legal Council (OCC 7638)

TEXT:

This responds to your letter of August 6, 1992, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108.

You write with reference to an amendment that became effective December 1, 1991, requiring a minimum of 12 square inches of lens area for rear stop or turn signals on vehicles over 80 inches wide, regardless of the separation between lamps. You request confirmation of your feeling that "equipment manufactured prior to December 1, 1991 would be exempt from this ruling", and that "it only applies to equipment that is manufactured after December 1, 1991." You have asked for this interpretation to "ensure compliance with our equipment fleet."

What the amendments require is that multipurpose passenger vehicles, buses, trucks, and trailers whose overall width is 80 inches or more, which are manufactured on and after December 1, 1991, be equipped with stop and turn signal lamps that meet the new requirements. Stop and turn signal lamps which were manufactured prior to that date that do not meet the new requirements are permissible to replace original equipment of the same type on vehicles manufactured before December 1, 1991, but they cannot be used as either original or replacement stop and turn signal lamps on vehicles manufactured on and after December 1, 1991. Furthermore, Standard No. 108 continues to allow manufacture and sale on and after December 1, 1991, of the old type of stop and turn signal lamps for replacement of original equipment on vehicles manufactured prior to December 1, 1991.

I hope that this assists you with your compliance question. We shall be pleased to answer any further questions you may have.

ID: nht81-3.42

Open

DATE: 11/20/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Fruehauf Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent letter to Mr. Kratzke of my staff concerning the requirements of Federal Motor Vehicle Safety Standard No. 120 (49 CFR @ 571.120). Specifically, you asked if retreaded tires could be mounted on new trucks and trailers, and what requirements those tires would have to meet.

Retreaded tires can be mounted on new trucks and trailers without violating Standard 120. For your information, I have enclosed a copy of a 1978 interpretation concerning Standard 120 which explains that retreaded tires can be mounted on new trucks and trailers in compliance with the standard. The only requirements those tires would have to meet is that the sum of the maximum load ratings for the tires would have to be at least equal to the gross axle weight rating of the axle to which they were fitted, as specified in section @ 5.1.2 of the Standard 120. As explained in the attached letter, there is no requirement that the retread meet the requirements of Standard 119 because those requirements are inapplicable to retreads. Further, there is no requirement that the retreads have the DOT symbol.

If you have any further questions, please contact Mr. Kratzke at (202) 426-2992.

ID: nht71-3.13

Open

DATE: 06/02/71

FROM: L. R. SCHNEIDER -- NHTSA; SIGNATURE BY DAVID SCHMELTZER

TO: Long Mile Rubber Company

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter to Mr. Van Orden dated May 20, 1971.

Tires retreaded prior to the effective date of the retread standard (January 1, 1972) are not permitted to contain the DOT symbol on the tire. If you have marked your matrices with the symbol, I suggest you buff the letters off the tire after it is retreaded, or remove the symbol from the matrix, or fill in that portion of the matrix.

The retreading of tires without the DOT markings before the effective date of the standard is permissible.

ID: 77-5.2

Open

TYPE: INTERPRETATION-NHTSA

DATE: 12/12/77

FROM: AUTHOR UNAVAILABLE; Joseph J. Levin Jr.; NHTSA

TO: Gould; Reichert & Strauss

TITLE: FMVSR INTERPRETATION

TEXT: This confirms the substance of your November 2, 1977, meeting with Roger Tilton of my staff concerning the applicability of the new Federal school bus safety standards to common carriers used in urban and rural transportation.

You indicated in that meeting that you thought that the effect of the Urban Mass Transportation Administration's grant program to rural transit authorities would be to phase out the standard yellow school bus in favor of transporting children on rural transit buses. This situation would result in the avoidance of the Federal school bus regulations.

It is the opinion of the National Highway Traffic Safety Administration (NHTSA) that buses used by rural transportation districts to transport school children do not qualify for the limited exception from the school bus safety standards accorded to urban transportation common carriers.

The agency has traditionally excluded urban common carrier buses from the school bus requirements to allow transportation of school children on existing urban transportation facilities. The agency has never extended this exclusion to rural common carrier buses. In our notice on the redefinition of school bus (40 FR 60033) the NHTSA indicated that only urban transit buses would fall within the ambit of this limited exception. By that action, the agency intended to avoid the artificial development of rural transportation authorities that would result in the avoidance of the Federal school bus regulations.

In another comment you criticized the agency's adoption of a "use definition" for the applicability of the school bus regulations since the application of such definition depends upon the sales transaction to establish the intended use of the vehicle. You allege that enforcement of regulations dependent upon the sales transaction cannot be achieved.

The agency adopted the "use definition" for the regulation of school buses as a result of a Congressional directive in the Motor Vehicle and School Bus Safety Amendments of 1974 (Pub. L. 93-492). Congress defined school bus in a manner that requires the use of a vehicle to be considered. Accordingly, the agency must employ the "use definition" in regulating school buses. The NHTSA does not agree that the new regulations are unenforceable as a result of this regulatory approach. Enforcement of these regulations will be as vigorous as the enforcement of any other NHTSA regulation.

ID: 86-2.7

Open

TYPE: INTERPRETATION-NHTSA

DATE: 03/17/86

FROM: STEPHEN T. WAIMEY; DEAN HANSELL -- LAW OFFICE OF DONOVAN LEISURE

TO: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TITLE: FMVSS 103 AND 104

ATTACHMT: ATTACHED TO LETTER DATED 12/29/86, TO STEPHEN J WAIMEY FROM ERIKA Z JONES, REDBOOK A29 (4) STANDARD 103 AND 104

TEXT: Dear Ms. Jones:

We write on behalf of Porsche to verify our understanding of a portion of FMVSS 103 (Windshield Defrosting and Defogging Systems) and 104 (Windshield Wiping and Washing Systems). Our question concerns the method of determining the areas to be included in calculating the percentages required to be wiped or defrosted under FMVSS 103 and 104.

Porsche is considering a windshield design that would be 5% smaller than the "A" area, as defined by the angles set forth in SAE J903c (Passenger Car Windshield Wiper Systems) and SAE J902b (Passenger Car Windshield Defrosting Systems). Our understanding is that, for the purpose of determining compliance with the percentages of the "A" area required to be wiped or defrosted under FMVSS 103 and 104, the percentages are based on the actual windshield size (less a one inch border) rather than the theoretical size that is derived from an abstract application of the specified angles in the SAE procedures.

Our conclusion is based on statements contained in SAE J903c, which is incorporated into FMVSS 104, S4.1.2, and SAE J902b, which is incorporated in FMVSS 103, S4.2. Both SAE J903c and J902b provide that "the areas used in determining the percentage of [wiped or defrosted] area are

those areas on the exterior glazing surface which are not within 1 (one) inch of the edge of the daylight opening." Thus, it is only the area that falls on the windshield itself, and excluding a one inch border at the outer edge of the exterior glazing surface, that need be used in calculating the appropriate percentages.

If our interpretation is correct, then any part of Area A (as determined by the given angles) that falls outside the windshield's physical area is immaterial.

A prompt response would be appreciated. Many thanks.

Yours truly,

ID: nht95-2.55

Open

TYPE: INTERPRETATION-NHTSA

DATE: April 26, 1995

FROM: John Womack -- Acting Chief Counsel; NHTSA

TO: Richard Kreutsiger -- Executive Director NYSBDA

TITLE: NONE

ATTACHMT: ATTACHED TO 2/11/95 LETTER FROM RICHARD KREUTZIGER TO WALTER MYERS

TEXT: Dear Mr. Kreutsiger:

This responds to your facsimile request for an interpretation of the question "is there any Federal mandate . . . that provides a specific date or time frame in which a manufacturer has to change model year dating . . . if there is no change in the vehic le production or design makeup." I apologize for the delay in responding. The short answer to your question is that our regulations require model years to change within a two year time frame but do not prescribe the date that may be selected for the mod el year changeover.

Regarding this agency's regulations, your letter indicated that you had found the provision in 49 CFR part 565, Vehicle Identification Number - Content Requirements, specifying that the model year must be included as part of the vehicle identification nu mber (VIN). You may not have noticed that section 565.3(h) of that part defines "model year" as "the year used to designate a discrete vehicle model irrespective of the calendar year in which the vehicle was actually produced, so long as the actual peri od is less than two calendar years." Therefore, even if a vehicle is identical to the vehicles produced in any number of preceding years, the model year must change at a frequency of less than two years.

My understanding is that your letter is only concerned with model years for school buses, which are not subject to the corporate average fuel economy program under Chapter 329 of title 49 of the U.S. Code. For passenger cars and light trucks, model year is defined in section 32901(15) for fuel economy purposes as "the annual production period of a manufacturer, as decided by the [EPA] Administrator, that includes January 1 of that calendar year; or that calendar year if the manufacturer does not have a n annual production period."

I hope this information is helpful. If you have any questions, please contact Paul Atelsek of my staff at this address or at (202) 366-2992.

ID: nht93-6.20

Open

DATE: August 18, 1993

FROM: Jack McIntyre -- V.Pres., Tie Tech Inc.

TO: John Womack -- Office of Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 11/23/93 from John Womack to Jack McIntyre (A41; Std. 209; Std. 222) and letter dated 9/15/93 from Jack McIntyre to John Womack (OCC-9123)

TEXT:

In January 1993, the National Highway Traffic Safety Administration issued requirements for wheelchair securement systems that are used on school buses. These requirements are included in Federal Motor Vehicle Safety Standard 222. As stated in the comments that were provided to the Proposed Rule, these standards are needed.

In reviewing the final requirements, however, it appears that a particular requirement for the wheelchair securement system was adopted that is inconsistent with the securement systems being manufactured by most wheelchair securement manufacturers. Also, this requirement does not appear to be directly relevant to the crash performance of a wheelchair securement belt. The specific requirement I am referring to appears in S5.4.2, which references the requirements of Type 1 safety belts of FMVSS 209, and requires that the belt webbing be not less than 1.8 inches wide.

There is no apparent need to specify a minimum belt width for wheelchair securement belts as there is for occupant restraint belts. I understand that the belt width requirements for occupant restraint systems is to spread the crash forces over a larger area of the body. There is no such need for securement belts. Currently the industry standard for securement belts is a 1 inch wide belt made from polyester that easily meets the 6,000 pound force requirements of FMVSS 209 and 222. Additionally, the 1 inch wide belts made from polyester have less stretch than the 1.8 inch nylon belts.

Finally, it is noted that 1 inch wide securement belts and related hardware are easier and less cumbersome to connect to a wheelchair, particularly in the tight circumstances that exist on school buses in many instances, than are the 1.8 inch wide belts and their larger pieces of hardware.

Based on the above, I petition to change the requirement that the wheelchair securement belt must be at least 1.8 inches wide. The cost to the wheelchair securement industry to retool for the wider belts would be significant, without any added benefits in terms of safety to occupants of wheelchairs in school buses.

Thank you for your consideration.

ID: nht71-3.8

Open

DATE: 05/25/71

FROM: AUTHOR UNAVAILABLE; Lawrence R. Schneider; NHTSA

TO: Distributers Association

TITLE: FMVSR INTERPRETATION

TEXT: This is response to your letter of May 12, 1971, in which you inquired about the responsibilities, under Parts 567 and 568 of the NHTSA regulations, of a company that sells small trailer chassis in kit form, to persons who assemble them, add bodies, and sell them to users. You discussed the questions by telephone with Richard Dyson of this office on May 21, and this letter confirms the answers that Mr. Dyson gave you then.

Since the unit sold by the company in question is not assembled, it is not an "incomplete vehicle" within the meaning of Part 568, and the company therefore has no responsibilities under that part to provide information to subsequent purchasers. The person who assembles the kit and adds a body is, of course, a manufacturer, and must certify the complete vehicle under @ 567.4 of the Certification regulations. It appears that this certifier would normally rely on the chassis kit seller to provide the basic information concerning the vehicle characteristics, and the assurance that when assembled according to instructions it will conform to applicable motor vehicle safety standards, so that he can responsibly certify the vehicle. We assume that the chassis kit seller would provide this information as a commerical responsibility, although the relationship is not at present governed by NHTSA regulations.

Please let us know if we can be of further assistance.

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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