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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 13181 - 13190 of 16517
Interpretations Date

ID: nht93-2.1

Open

DATE: 03/01/93

FROM: THOMAS C. BALOGA -- MANAGER, SAFETY ENGINEERING, MERCEDES - BENZ

TO: JOHN WOMACK -- ACTING CHIEF COUNSEL, NHTSA

COPYEE: JERRY SONOSKY -- HOGAN & HARTSON

TITLE: LONGER SEAT BELT FOR OVER-SIZE MERCEDES-BENZ OWNER

ATTACHMT: ATTACHED TO LETTER DATED 3-10-93 FROM JOHN WOMACK TO THOMAS C. BALOGNA (A40; VSA 108 (a)(2)(A); STD. 209)

TEXT: This refers to my telephone discussion with Ed Glancy on March 1, 1993 concerning a longer seat belt.

Mercedes-Benz of North America, Inc. has been contacted by the owner of a Mercedes-Benz car who cannot use the driver-side seat belt because of his large body size (approx. 500 lbs). Since our special order 12 inch longer belt is still too short, our factory has supplied a 30 inch longer-than-standard seat belt for installation in this man's car. The extra-long belt assembly will not comply with the following aspects of Standard 209:

- seat belt will not completely roll-up into B-pillar due to excessive webbing on spool;

- seat belt not tested for retraction spring durability therefore may not pass the retractor cycle test;

- no certification label is attached.

We ask that you please advise us as soon as possible whether NHTSA will, under these circumstances, exercise appropriate discretion in non-enforcement of Standard 209 for this special seat belt installation. This discretion would be similar to Chief Counsel interpretations concerning non-enforcement of Standards when special equipment for handicapped drivers is installed. Without this action from you, the man will not be protected by a seat belt. We know that requests for extra long seat belts are likely to continue and we ask that you please advise us whether Mercedes-Benz of North America, Inc. needs to advise you of each and every special installation or whether it is sufficient for us to keep appropriate records of the VIN etc. It is our intention to advise the owner to have the original belt re-installed before selling the car.

Thank you for your quick response.

ID: nht93-2.10

Open

DATE: March 8, 1993

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Fredd Scheys -- President S.C.C. CARAT Inc.

TITLE: NONE

ATTACHMT: Attached to 1/27/95 letter from Philip R. Recht to Fredd Scheys (A43; Sec. 1397(b)(2); Also attached to 1/25/95 fax from Fredd Scheys to John Womack; Also attached to 11/16/92 letter from Paul Rice to Fredd Scheys

TEXT: Dear Mr. Scheys:

This responds to your FAX of March 2, 1993, to Taylor Vinson of this Office. You have heard that Paul Jackson Rice is no longer Chief Counsel of this agency and you request confirmation that his letter to you of November 16, 1992, remains valid.

The opinion rendered you approximately 4 months ago remains unchanged and valid.

For your information, once an interpretation has been issued by this Office, it remains in effect regardless of who may be Chief Counsel. Generally, an interpretation is affected only if the statute or regulation upon which it is based is amended. The interpretation furnished you was based upon the National Traffic and Motor Vehicle Safety Act and 49 CFR Part 567. Neither the Act nor Part 567 has been amended since November.

Sincerely,

ID: nht93-2.11

Open

DATE: March 9, 1993

FROM: D. E. Dawkins -- Director, Vehicle Compliance and Safety Affairs, Chrysler Corporation

TO: John Womack -- Acting Chief Counsel, NHTSA

TITLE: Re: NHTSA Letter of February 18, 1993 Regarding the Chrysler Corporation Petition to Manufacture 10 Chesapeake Consortium Electric Vehicles

ATTACHMT: Attached to letter dated 3-24-93 from John Womack to Dale E. Dawkins (A40; Part 555)

TEXT: This letter responds to your referenced letter and the subsequent phone conservation with Mr. Len Blazic of my staff on March 1, 1993.

Chrysler Corporation desires to manufacture ten Chesapeake Consortium Electric Vehicles (CCEV'S) that would have no discernable safety differences to the electric TEVan vehicles, which have already been granted exemption from three MVSS's. All compliance aspects of this program remain unchanged from that of the TEVan program. The only difference between the two programs of electric vehicle development is the propulsion motors and transmissions, as were outlined in our December 16, 1992 letter.

We believe that this will satisfy your need for additional information.

ID: nht93-2.12

Open

DATE: 03/10/93

FROM: JOHN WOMACK -- ACTING CHIEF COUNSEL, NHTSA

TO: THOMAS C. BALOGA -- MANAGER, SAFETY ENGINEERING, MERCEDES-BENZ OF NORTH AMERICA, INC.

COPYEE: JERRY SONOSKY -- HOGAN & HARTSON

TITLE: NONE

ATTACHMT: ATTACHED TO TELEFAX MEMORANDUM DATED 3-1-93 FROM THOMAS C. BALOGA TO JOHN WOMACK (OCC 8353)

TEXT: This responds to your letter asking whether the National Highway Traffic Safety Administration (NHTSA) will exercise its discretion not to institute enforcement proceedings with respect to a special seat belt installation in a Mercedes-Benz car owned by a man who weighs approximately 500 pounds. You stated that the owner cannot use the driver-side seat belt because of his large body size and that your special order 12-inch longer belt is still too short. You indicated that your factory has supplied a 30-inch longer seat belt, but that the extra-long belt assembly will not comply with the following aspects of Standard No. 209:

--the seat belt will not completely roll up into the B-pillar due to excessive webbing on the spool;

--the seat belt has not been tested for retraction spring durability and therefore may not pass the retractor cycle test;

--no certification label is attached.

As you are aware, our agency is authorized to issue Federal motor vehicle safety standards that set performance requirements for new motor vehicles and items of motor vehicle equipment. Manufacturers are required by the National Traffic and Motor Vehicle Safety Act (Safety Act) to certify that their products conform to our safety standards before they can be offered for sale. Manufacturers, distributors, dealers and repair businesses modifying certified vehicles are affected by @ 108 (a) (2) (A) of the Safety Act. It prohibits those businesses from knowingly rendering inoperative any elements of design installed on a vehicle in compliance with a safety standard.

In certain limited situations in the past where a vehicle must be modified to accommodate the needs of a person with a particular disability, NHTSA has stated that it would consider certain violations of Safety Act provisions as purely technical ones justified by public need, and that it would not institute enforcement proceedings. This is to advise you that we will take this position for the specific factual situation cited above, as we equate the special needs of a 500 pound individual with the needs associated with a disability. I note that we expect manufacturers to provide complying seat belts that are appropriate for the normal range of occupant sizes, including large persons. Mercedes-Benz appears to do this, as it provides a (presumably complying) special order 12-inch longer belt for large persons. We recognize that a 500 pound individual is outside the normal range of occupant sizes.

You stated that requests for extra long seat belts are likely to continue and asked whether Mercedes-Benz needs to advise NHTSA of each and every special installation or whether it is sufficient to keep appropriate records of the VIN. I note that if the agency was presented again with the same factual situation, we would expect to make the same decision. However, we would want to be advised of each such special installation. One of the factors behind our position is the special nature of the factual situation. If Mercedes-Benz wanted to provide extra long seat belts on a routine basis, we would expect it to provide a design that fully complies with Standard No. 209.

ID: nht93-2.13

Open

DATE: 03/11/93

FROM: JOHN WOMACK -- ACTING CHIEF COUNSEL, NHTSA

TO: THOMAS L. WRIGHT -- COORDINATOR, TECHNICAL SUPPORT UNIT, STATE OF NEW JERSEY, DEPARTMENT OF LAW AND PUBLIC SAFETY, DIVISION OF MOTOR VEHICLES

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 12-29-92 FROM THOMAS L. WRIGHT TO PATRICK BOYD (OCC 8210)

TEXT: This responds to your letter to Patrick Boyd of the National Highway Traffic Safety Administration's (NHTSA's) Office of Vehicle Safety Standards, concerning window tinting. Your letter has been referred to my office for reply.

Your questions relate to a January 22, 1992 (57 FR 2496) notice of proposed rulemaking (NPRM) on the tinting requirements of Safety Standard No. 205, "Glazing Materials." You ask about the status of the NPRM. The agency received a large number of comments on this rulemaking. We have reviewed the comments and are analyzing the issues raised in this rulemaking.

You also ask about a statement in the NPRM about Federal preemption of state window tinting laws. You ask whether Federal law preempts a state law that permits add-on window tinting material for medical or aesthetic reasons.

As explained below, the answer is no, provided that the state law regulates conduct other than that regulated by Federal law. Your question was addressed in the NPRM's discussion of the Federalism implications of the proposed rule (p. 2507).

By way of background, NHTSA issued Standard 205 under the authority of the National Traffic and Motor Vehicle Safety Act. The standard currently imposes a minimum level of light transmittance of 70% in all areas requisite for driving visibility (which includes all windows on passenger cars). The primary purpose of this requirement is to ensure adequate visibility through the windows, thereby reducing the risk of a motor vehicle crash.

Section 103(d) of the Safety Act provides that:

Whenever a Federal motor vehicle safety standard . . . is in effect, no State or political subdivision of a State shall have any authority either to establish, or to continue in effect, with respect to any motor vehicle or item of motor vehicle equipment any safety standard applicable to the same aspect of performance of such vehicle or item of equipment which is not identical to the Federal standard.

Whether state law is preempted under @ 103(d) depends in part on the conduct that is regulated by that law. Federal safety standards regulate the manufacture and sale of new motor vehicles and new items of motor vehicle equipment. State law would be preempted to the extent it established performance requirements applicable to the manufacture of vehicles or glazing that differ from those in Standard 205. State law would also be preempted if it purported to allow the manufacture or sale of glazing materials or new vehicles containing glazing material that did not meet the specifications of Standard 205.

Federal law also regulates modifications made to new and used vehicles by motor vehicle manufacturers, distributors, dealers and repair businesses. Section 108(a)(2)(A) of the Safety Act provides that:

No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative, in whole or in part, any device or element of design installed on or in a motor vehicle . . . in compliance with an applicable Federal motor vehicle safety standard.

The effect of this is to impose limits on the tinting practices of businesses listed in @ 108(a)(2)(A). These businesses may not install tinting on new or used vehicles that reduces the light transmittance of windows covered by Standard 205 to a level below the Federal requirement of 70 percent. A state law would be preempted if it purported to allow modifications violating Standard 205 by these named businesses. Section 108(a)(2)(A) does not apply to actions by individual vehicle owners.

Because Federal safety standards regulate the manufacture and sale of new motor vehicles, state requirements applicable to the registration and inspection of motor vehicles after the first sale to a consumer are not preempted merely because they are not identical to the Federal safety standards, as long as they do not interfere with the achievement of the purposes of Federal law. Therefore, a state could permit the registration of a vehicle which had been altered by its owner by the addition of window tinting, even when the tinting reduces the light transmittance below the Federal standard. However, the state cannot legitimize conduct - the rendering inoperative of glazing by commercial businesses installing window tinting - that is illegal under Federal law.

I have enclosed a copy of the Report to Congress on Tinting of Motor Vehicle Windows which you requested. I hope you find this information helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992.

ID: nht93-2.14

Open

DATE: March 11, 1993

FROM: Samuel Kimmelman

TO: Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3-31-93 from John Womack to Samuel Kimmelman (A41; Std. 108); Also attached to letter dated 11-1-89 from Stephen P. Wood to Samuel Kimmelman

TEXT: Enclosed is a copy of a letter dated Nov. 1, 1989 from NHTSA, signed by the then Acting Chief Counsel Stephen P. Wood.

In the next to last paragraph Mr. Wood states that NHTSA requires the front hazard waning lamps must continue to operate even when the stop lamps are activated.

Does NHTSA continue to hold to the requirement as put forth in Mr. Wood's letter or has this requirement been revised?

ID: nht93-2.15

Open

DATE: March 12, 1993

FROM: Scott R. Dennison -- Vice President, Production, Excalibur Automobile Corporation

TO: Robert Hellmuth -- Director, Office of Vehicle Safety Compliance, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 4-19-93 from John Womack to Scott R. Dennison (A41; Part 555)

TEXT: I am writing on behalf of the Specialty Car Industry in general and Excalibur in particular to offer my input and assistance regarding the alleged debate over the treatment of vehicles replicating pre-safety standard vehicle designs and their compliance with current Federal Motor Vehicle Safety Standards. This has long been a difficult area for the industry to understand since most of the manufacturers of these vehicles are ultra low volume manufacturers. I was briefly involved with the limousine industry in 1989 when NHTSA began to work cooperatively with them to achieve practical compliance and would like to see the our industry and NHTSA do the same.

As you are aware, the Environmental Protection Agency has created a very specific set of guidelines for the specialty car industry to allow them to produce compliant automobiles without the need for "legitimate" FTP-testing. It is my opinion that the same type of policy is possible to bring the specialty cars up to an acceptable standard where there are those who now fall short. I also believe that we, as a $100 million plus industry, can internally weed out the undesirable, poor quality builders and manufacturers and essentially police ourselves, not unlike the limousine converters. The biggest hurdle this industry faces is a way to interpret and apply the "rules" in a cost effective manner which will allow us to remain in business.

I am aware that the "Hot Rod" industry is heavily engaged in the same type of effort at this time. However, they have an advantage that we do not have as most hot rods and muscle cars were produced by major "legitimate" manufacturers and were "real" cars at one time. Even though we may build a car replicating a 1934 Mercedes or a 1966 Cobra, we are still building a 1993 vehicle requiring 1993 compliance. In most cases, the original body style necessary for marketing reasons does not readily lend itself to current compliance regulations. Ergo, our dilemma.

I would like to hear your opinion and would look forward to participating in the decision making process wherever possible. Please let me know what I can do to assist. I am looking forward to your response.

ID: nht93-2.16

Open

DATE: March 15, 1993

FROM: Kirk Brown -- Secretary, Illinois Department of Transportation

TO: John Womack -- Acting Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 4-22-93 from John Womack to Kirk Brown (A41; VSA S108(a)(2)(A); FMVSS 124)

TEXT: I am requesting your opinion whether modifying the throttle controls on a school bus so that a short person can operate it would jeopardize the manufacturer's certification that a bus is in compliance with the Federal Motor Vehicle Safety Standards. I have enclosed a copy of a letter from School Services and Leasing, Inc. which has requested this opinion from the state of Illinois and, apparently, other states. Rather than have each state render possibly differing opinions on this question, it would be appropriate for NHTSA to respond to this company's questions.

If it is your opinion that this modification would violate Federal Motor Vehicle Safety Standards for buses, would you also advise this company whether it might obtain a waiver for this modification for particular buses.

I look forward to a response to these questions from you.

Attached to letter dated 2-22-93 from George Marter, School Services and Leasing, Inc. to Curt Brown, Illinois Department of Transportation.

(Text omitted)

ID: nht93-2.17

Open

DATE: March 16, 1993

FROM: Steve Thomas -- General Manager, Texas Bragg Enterprises

TO: Walter Meyers -- NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 4-14-93 from John Womack to Steve Thomas (A41; Std. 119; Std. 120)

TEXT: I have several of my dealers that are wanting to buy their trailers from me without tires or without tires and wheels.

I am reasonably sure that they do not have fourteen (14) customers at a time wanting to put their own tires and wheels on their trailers. I do believe that they will be installing used tires or used tires and wheels on these trailers once they got them to their places of business. Since I know this is against the law can I legally sale the trailers to my dealers like this and if so, do I need them to sign some kind of waiver or a form stating they bought the trailers from me without tires or wheels?

ID: nht93-2.18

Open

DATE: March 16, 1993

FROM: Bob Brinton -- Friction Advisory Service

TO: Office of Chief Council -- U.S. Department of Transportation, NHTSA

TITLE: Subject: Interpretation of Parking

ATTACHMT: Attached to letter dated 5-6-93 from John Womack to Bob Brinton (A41; Std. 121); Also attached to letter dated 12-9-76 from Frank A. Berndt to Leon W. Steenbock (Std. 121)

TEXT: According to FMVSS 121 a mechanical locking device must be in place within 3 seconds of actuating the parking brake control. In the case of some vehicles, especially refuse type trucks with right hand side drive, there are several systems that use either an I.C.C. flip switch valve or a push pull valve to park the vehicle on air only when the driver leaves the vehicle to pick up trash. The air park is used so that spring brakes are not applied avoiding extreme wear cycles on the spring. Is this type of parking considered legal or should all vehicles when they are parked and the driver leaves the cab have a mechanically held parking brake function? It is my understanding that new O.E.M. certified vehicles are being built with this air park work brake and many right hand drive conversion companies are also installing this type of air park configuration.

As an accident investigator I need to know if NHTSA considers this air park illegal or non-certifiable to meet the intentions of FMVSS 121 Sec. 5.6.3. Your prompt attention to this request is appreciated.

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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