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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 781 - 790 of 2066
Interpretations Date
 search results table

ID: nht78-2.26

Open

DATE: 04/05/78

FROM: AUTHOR UNAVAILABLE; M. M. Finkelstein; NHTSA

TO: C. S. Ullman

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 28, 1978, to Mr. A. P. Uccello, regarding Federal Motor Vehicle Safety Standard No. 202, Head Restraints (copy enclosed).

In this Standard, under section 4(b)(1), the minimum height of the head restraint shall not be less than 27.5 inches above the seating reference point which is determined with a three-dimensional H Point Machine per SAE Standard J826B placed on the seat. Thus, we have specified a minimum dimension that the car builder must comply with, but we have no limit on the maximum dimension of the head restraint. This latter dimension is set by the builder to suit his requirements.

Certainly your height is a problem in this case and for future rulemaking actions along this line we are placing your letter and the Buick reply in the appropriate docket.

SINCERELY,

February 28, 1978

A.P. Uccello Transportation Dept.

Dear Sir:

You are impossible to get on the phone so I will resort to writing.

I have nothing but plaudits for my '77 Buick but I have written to them about the height of the head restraint (head rests). I am 6' 7" tall and the head rest probably would not prevent whip lash in my case. Previously the head rest was made so it could lock in at least three positions-the highest position was correct for me. Now the head rest only tranerses about 1 inch and does not lock so people getting in the back seat could depress the head rest.

Enclosed please find copy of my reply from Buick. I call your attention to the second paragraph. I would like to know what safety standard effects the head rest? If there is such a standard, then it should be corrected.

I welcome your comment and advice.

THANK YOU.

Charles S. Ullmann

BUICK MOTOR DIVISION, GENERAL MOTORS CORPORATION January 31, 1978

S. C. Ullmann Associates, Inc. 94 Highland Road Scarsdale, NY 10583

Att: Mr. Charles S. Ullmann

Dear Mr. Ullmann:

Thank you for your recent note of January 23, 1978 addressed to our Zone Manager, Mr. R. G. Royer, and we appreciate the interest you have shown in bringing to our attention the characteristics of the front seat head rest supports in your 1977 Buick Electra Limited.

As you probably realize, your car was manufactured in compliance with many vehicle safety standards, and one of these considerations is the head rest suitability throughout the range and size of the car occupants.

However, since we welcome comments from all of our owners, it is with this thought that we are forwarding your letter to the attention of those parties responsible for these design caracteristics.

Thank you again for writing, and please be assured of our interest.

K. J. Mariano Manager, Zone Service Operations

ID: 1993y

Open

Mr. Taylor Hong
President, Fair Sun Industrial Co., Ltd.
P.O. Box 36-570
Taipei, Taiwan

Dear Mr. Hong:

This is in reply to your letter with reference to motor vehicle flashers that you wish to sell in the United States.

You have asked the following questions:

l. "How do we get DOT approval?" 2. "Should ask for an application forms from you and sent one lot of samples for your test?"

The Department has no authority to "approve" flashers, and no laboratory of its own in which it tests them. Under our law, the National Traffic and Motor Vehicle Safety Act, the manufacturer of the flashers, not the Department, determines in the first instance whether or not they comply with the SAE materials incorporated into Federal Motor Vehicle Safety Standard No. l08. If the manufacturer is convinced that they comply, it certifies that the flashers meet Standard No. l08, either with a statement on the container in which the flashers are shipped, a tag attached to each flasher, or a DOT symbol on the flasher itself. From time to time, the Department buys flashers for testing. In this manner, the Department has discovered that a number of those manufactured in Taiwan have not met Federal requirements, and lacked the required certification. In some instances, civil penalties have been imposed against the manufacturer or importer of the flashers.

3. "We may send samples to any other Laboratory and get an approval?"

To aid you in reaching a conclusion whether the flashers are designed to conform with Standard No. 108, you may send samples to any test laboratory you wish. Although the standard deems a flasher compliant if not less than 17 of 20 flashers tested meet the requirements, we caution you that you should not accept such a result as a guarantor of compliance. Because of the tolerances involved in production of flashers, we believe that a manufacturer wishing to ensure that at least 17 of 20 flashers will pass whenever the government tests them should design its flashers to achieve a higher level of compliance with durability and performance requirements than the minimum acceptable number of 17. Once a higher level is reached, a manufacturer should ensure that the flashers will continue to meet Standard No. l08 over time. Accordingly, we urge flasher manufacturers to test their products periodically as an assurance that a minimum of 17 out of every 20 continue to meet the performance and durability requirements specified.

Although you have no obligation to obtain "approval" from the Department, there are two requirements that manufacturers of flashers must meet before offering their products for sale in the U.S. You must designate an agent for service of process (49 CFR 551.45) and file an identification statement (49 CFR Part 566). I enclose a copy of these regulations for your information.

If you have any further questions we shall be pleased to answer them.

Sincerely,

Stephen P. Wood Acting Chief Counsel

Enclosures

/ref:108 d:9/l3/89

1970

ID: 1984-2.40

Open

TYPE: INTERPRETATION-NHTSA

DATE: 07/31/84

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Automobile Importers of America,Inc

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Bruce Henderson Automobile Importers of America, Inc. 1735 Jefferson Davis Highway, Suite 1002 Arlington, Virginia 1002 Dear Mr. Henderson:

This is in reply to your letter to Mr. Vinson of this office, in which you asked for an interpretation of Motor Vehicle Safety Standard No. 108. Specifically, you would like to know whether a supplementary turn signal unit may be added to each front fender near the wheel well of a vehicle already equipped with a turn signal system meeting Standard No. 108. You also asked whether there were any restrictions on the mounting height of such a lamp.

Standard No. 108 allows lighting equipment additional to that required by the standard provided that it does not impair the effectiveness of the lighting equipment that the standard requires (paragraph S4.1.3). The supplementary turn signal unit that you describe would appear to enhance the effectiveness of the required turn signals rather than detract from them. There is no requirement that equipment, added at the option of the manufacturer, meet the specific requirements of the standard applicable to identical or similar items of equipment; i.e., the supplementary unit is not legally required to have the same flash rate as the primary turn signals, nor is it subject to the same mounting height restrictions. Obviously, if these specifications are met, supplementary equipment is less likely to impair the effectiveness of the required equipment within the meaning of S4.1.3.

As you are no doubt aware, some manufacturers are wiring their front side marker lamps to flash with the turn signals. This type of supplementary system is acceptable to us.

I hope that this answers your questions.

Sincerely,

Frank Berndt Chief Counsel

July 17, 1984

Mr. Taylor Vincent Office of Chief Counsel - NOA-30 National Highway Traffic Safety Administration 400 Seventh Street, SW Washington, DC 20590

Dear Mr. Vincent:

We would like to request all interpretation of the application of Federal Motor Vehicle Safety Standards (in particular, FMVSS 108) in the following case:

A passenger car complies fully with the requirements for turn signals in FMVSS 108. Is it permissable to add a "turn signal repeater lamp" to each front fender near the wheel well? This repeater lamp would indicate to a vehicle in an adjacent lane an intention to change lanes. The vehicle would continue to to meet requirements in FMVSS 108 for rate of flash, bulb burnout indications, etc.

If the use of such turn signal repeaters in addition to the "four-corner" signal lamps is permissible, is there any restriction on the mounting height - maximum or minimum?

Thank you for your attention and assistance in this matter.

Sincerely, Bruce Henderson BH:bd

ID: aiam1735

Open
Mr. Robert A. Danis, Carlton Manufacturing Company, 1152 High Street, Central Falls, Rhode Island 02863; Mr. Robert A. Danis
Carlton Manufacturing Company
1152 High Street
Central Falls
Rhode Island 02863;

Dear Mr. Danis: This is in response to your letter of October 23, 1974, requesting ou comments on your West Coast type mirror (which includes a ground-in convex spot mirror) and information on Federal regulations for spot mirrors in general.; Standard No. 111, *Rearview Mirrors*, provides minimum performanc requirements for rearview mirrors on passenger cars and multipurpose passenger vehicles. According to the standard, the outside rearview mirror required to be placed on the driver's side of the vehicle must be furnish the driver with a specified field of view to the rear of substantially unit magnification. As long as the mirror is capable of satisfying these field view requirements, the inclusion of a convex spot mirror no the plane mirror (as with the West Coast mirror) is not prohibited by the standard. If your West Coast type mirror is capable of providing the required view of substantially unit magnification independent of its convex spot mirror, it will comply with the standard.; The recent notice proposing to amend the rearview mirror standard (Ma 1, 1974, 39 FR 15143), does not alter the above described permissible use of West Coast type mirrors. No requirements for spot mirrors are contained in the Federal motor vehicle safety standards.; We appreciate your interest. Yours truly, Richard B. Dyson, Acting Chief Counsel

ID: aiam1580

Open
Mr. Raymond E. Jones, Project Engineer, Dura Corporation, Fords Mill Road, Paris, KY 40361; Mr. Raymond E. Jones
Project Engineer
Dura Corporation
Fords Mill Road
Paris
KY 40361;

Dear Mr. Jones: This responds to Dura Corporation's July 24, 1974, questions whethe S5.6 of Standard No. 121, *Air brake systems*, requires parking brakes on air suspension liftable axles, and whether the 'no lockup' requirements of the standard apply to a liftable axle on a 'tandem axle rig'.; The parking brake performance options of S5.6 do not require parkin brakes on an air suspension liftable axle such as you describe. S5.6.2 requires only that the parking brakes installed on a vehicle meet minimum performance levels. S5.6.1 requires parking brake retardation force on 'an axle other than a steerable front axle'. We do not consider this requirement to apply to an axle which is not on the ground when the parking brake system is activated.; The standard's 'no lockup' requirement (S5.3.1) applies to >>>'any wheel at speeds above 10 mph except for . . . (b) Lockup of wheels on nonsteerable axles other than the two rearmos nonliftable, nonsteerable axles on a vehicle with more than two nonsteerable axles.<<<; Under this provision, if a vehicle has two nonliftable, nonsteerabl axles at the rear which do not lock up (such as an antilock-equipped tandem axle rig) it may be equipped with a liftable nonsteerable axle which does not meet the 'no lockup' requirements.; Yours truly, Richard B. Dyson, Acting Chief Counsel.

ID: aiam2866

Open
Mr. Robert B. Kurre, Director of Engineering, Wayne Corporation, P. O. Box 1447, Industries Road, Richmond, IN 47374; Mr. Robert B. Kurre
Director of Engineering
Wayne Corporation
P. O. Box 1447
Industries Road
Richmond
IN 47374;

Dear Mr. Kurre: This responds to your recent letter asking whether Safety Standard No 208, *Occupant Crash Protection*, does require side- facing seats in multipurpose passenger vehicles to comply with one of the options under paragraph S4.2.2, since the side-facing seats in question would be considered designated seating positions. If a manufacturer chooses to install seat belts under one of the options of that paragraph, the seat belt assemblies must comply with Safety Standard No. 209, *Seat Belt Assemblies*, and Safety Standard No. 210, *Seat Belt Anchorages*.; Safety Standard No. 210 does exempt side-facing seats from its strengt requirements, but all other requirements of the standard would be applicable. However, we strongly recommend that belt anchorages for side-facing seats be of at least equivalent strength to anchorages for forward and rearward facing seats, since the strength specifications are only minimum performance requirements. Side-facing seats were excepted from the strength requirements specified in the standard because the forces acting on side-facing seats are different from those acting on forward or rearward facing seats and the requirements and procedures were specifically developed for these latter seats.; Please contact this office if you have any further questions. Sincerely, Joseph J. Levin, Jr., Chief Counsel

ID: aiam3371

Open
Mr. Stephen E. Mulligan, International Harvester, 401 North Michigan Avenue, Chicago, IL 60611; Mr. Stephen E. Mulligan
International Harvester
401 North Michigan Avenue
Chicago
IL 60611;

Dear Mr. Mulligan: This is in response to your letter of October 1, 1980, in which you as whether compliance with 49 CFR 567, Certification, will satisfy the requirements of S4.3 of Federal Motor Vehicle Safety Standard No. 115, 49 CFR 571.115.; Section 4.3 of Federal Motor Vehicle Safety Standard No. 115 require that the vehicle identification number (VIN) 'appear clearly and indelibly upon either a part of the vehicle other than the glazing that is not designed to be removed except for repair or upon a separate plate or label which is permanently affixed to such a part.' S4.3.1 requires each character to appear in a capital, sans serif typeface. In the case of passenger cars and trucks of 10,000 pounds or less GVWR, each character must have a minimum height of 4 mm. S4.4 specifies that the VIN for passenger cars and trucks of 10,000 pounds or less GVWR shall be located within the passenger compartment.; Section 567.4 of Part 567, Certification (49 CFR 567), requires tha the certification label be permanently affixed to the vehicle, and display the vehicle identification number. Consequently, for all vehicles except passenger cars and trucks of 10,000 pounds or less GVWR, compliance with S 567.4 of Part 567 would also effect compliance with S4.3 of Standard No. 115 so long as capital, sans serif typeface was used.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam0678

Open
Louis C. Lundstrom, Director, Automotive Safety Engineering, General Motors Environmental Staff, General Motors Technical Center, Warren, Michigan 48090; Louis C. Lundstrom
Director
Automotive Safety Engineering
General Motors Environmental Staff
General Motors Technical Center
Warren
Michigan 48090;

Dear Mr. Lundstrom: This is in reply to your letter of March 28, 1972, requestin elaboration of a statement made in the preamble to Motor Vehicle Safety Standard No. 125, Warning Devices. You asked that the NHTSA identify the specific data it used in determining that with respect to wide angle positioning of the device, a lower minimum candlepower than that required by the E.C.E. Provides adequate protection.; As I said in my letter to you of March 27, 1972, in response to similar request, a large amount of material has been placed in this public docket as background for the rulemaking action. All of this material has been carefully studied by the NHTSA, and together with the expertise and judgment of NHTSA personnel, relied on in reaching the decisions involved in issuing this standard. In informal rulemaking proceedings, the decisions are based on the total weight of the agency's knowledge, not on particular items of information.; I will comment, however, that some of the materials relating to th passage that you quoted were submittals from Chrysler Corporation (Nr. 147) and the California Highway Patrol (Nr. 143), and the University of California report on triangle reflector performance (General Reference Nr. 17, Attachment 2).; Sincerely yours, Robert L. Carter, Acting Associate Administrator Motor Vehicle Programs;

ID: aiam0938

Open
Mr. Bernard P. O'Meara, Center for Auto Safety, 800 National Press Building, Washington, DC 20004; Mr. Bernard P. O'Meara
Center for Auto Safety
800 National Press Building
Washington
DC 20004;

Dear Mr. O'Meara: Thank you for your letter of 29 November, 1972, concerning allege non-compliance of the Defect Information Report regarding Volkswagen Windshield Wipers, submitted by Volkswagen of America on October 12, 1972, with the requirements of NHTSA's Defect Reports Regulations, 49 CFR Part 573. We agree that Volkswagen has failed to supply information required by Sections 573.4(c)(2) and 573.4(c)(6) of the Regulation, specifically, the months of manufacture of the affected vehicles and a chronology which includes warranty claims, field service bulletins, and other such information. We are contacting Volkswagen to determine why the Company has failed to furnish that information and to attempt to obtain it. We also agree with your conclusion that 100% of 1948-1969 Volkswagens are potentially affected by the windshield wiper defect. However, Volkswagen's statement that 'no information is available' as to either the total number of such vehicles operating in the United States, or the percentage potentially affected satisfies the disclosure requirement of the regulation (49 CFR 573.4(c)(3, 4)).; We cannot agree, however, with your remaining assertions o non-compliance with the Regulations. While the Volkswagen Information Report is lacking in detail and is a poor example of an informational communication, it does contain minimal responses to the enumerated requirements of the Regulations.; Thank you for your interest in motor vehicle safety. Sincerely, Lawrence R. Schneider, Chief Counsel

ID: aiam1470

Open
Mr. William A. Goichman, Rozner and Yorty, Suite 1808, 10960 Wilshire Boulevard, Los Angeles, CA 90024; Mr. William A. Goichman
Rozner and Yorty
Suite 1808
10960 Wilshire Boulevard
Los Angeles
CA 90024;

Dear Mr. Goichman: This responds to your March 26, 1974, request for information on sea belt regulations as they concern reclining passenger seats.; Federal Motor Vehicle Safety Standard No. 208, *Occupant Cras Protection,* requires passenger cars to be equipped with seat belt assemblies, but it does not contain performance requirements to regulate the effectiveness of the belt assembly with the seating system in the reclining position.; Federal Motor Vehicle Safety Standard No. 207, *Seating Systems* specifies minimum safety requirements for motor vehicle seats. The requirements of the standard are based on conventional seat designs that normally incorporate a seat back angle of approximately 25 degrees rearward inclination from the vertical. Standard No. 207 requires that reclining seats be tested in their most upright position and does not require seats to be tested in the reclining position.; The National Traffic and Motor Vehicle Safety Act of 1966 preempt state motor vehicle safety regulations which are not identical to the Federal standards with regard to the same aspect of performance and therefore any state law would be identical to Standards Nos. 207 and 208 on these aspects of performance (15 U.S.C. S 1392 (d)).; The engineering staff is not aware of any studies in the area of sea belts and reclining seats.; Yours truly, Richard B. Dyson, Assistant Chief Counsel

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.