Pasar al contenido principal

Los sitios web oficiales usan .gov
Un sitio web .gov pertenece a una organización oficial del Gobierno de Estados Unidos.

Los sitios web seguros .gov usan HTTPS
Un candado ( ) o https:// significa que usted se conectó de forma segura a un sitio web .gov. Comparta información sensible sólo en sitios web oficiales y seguros.

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 521 - 530 of 2067
Interpretations Date

ID: aiam3733

Open
Mr. H. Nakaya, Manager, Mazda (North America) Inc., 23777 Greenfield Road - Suite 462, Southfield, MI 48075; Mr. H. Nakaya
Manager
Mazda (North America) Inc.
23777 Greenfield Road - Suite 462
Southfield
MI 48075;

Dear Mr. Nakaya: This is in response to your letter of July 8, 1983 asking for a interpretation of Motor Vehicle Safety Standard No. 108.; Section S4.2 of SAE Standard J588e *Turn Signal Lamps* establishes minimum distance of 4 inches from the optical axis (filament center) of the front turn signal to the inside diameter of the retaining ring of the headlamp providing the lower beam. You believe that it is not necessary to have a retaining ring on a semi-sealed headlamp and you have asked whether you may substitute the edge of the reflector (as shown on your drawing) to measure the dimension covered by S4.2 of J588e.; The point depicted on your drawing appears to be the inner edge of th reflector, rather than the extreme edge, nevertheless, the 'reflector edge' you have indicated is the approximate location of a retaining ring on a fully sealed headlamp, and is therefore acceptable as a measuring point under Standard No. 108.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam3507

Open
Mr. Katsuhiko Yokoi, Assistant Manager - Tech. Dept., Toyoda Gosei Co., Ltd., 1 Nagahata, Ochiai, Haruhi-mura, Nishikasugai-gun, Aichi-pref., 452 JAPAN; Mr. Katsuhiko Yokoi
Assistant Manager - Tech. Dept.
Toyoda Gosei Co.
Ltd.
1 Nagahata
Ochiai
Haruhi-mura
Nishikasugai-gun
Aichi-pref.
452 JAPAN;

Dear Mr. Yokoi: The answers to the questions in your letter of January 20, 1982, ar 'yes' to both questions.; >>>1. The 'adjacent layers' referenced in Federal Motor Vehicle Safet Standard (FMVSS) No. 106, paragraph S7.3.7, are (a) the inner tube and braided layer and (b) the braided layer and outer tube.<<<; >>>2. The adhesion requirements are met if both the tensile strength measured between (a) the inner tube and braided layer and (b) that between the braided layer and the outer cover are equal to or greater than 8lbs/inch as determined using the FMVSS No. 106 procedure. It should be noted that the 8lbs/inch value is an absolute minimum value as indicated in paragraph S8.6.4(a) of the standard.<<<; A copy of FMVSS No. 106 is included for your information. Sincerely, Vernon G. Bloom, Safety Standards Engineer

ID: aiam3547

Open
Mr. G. K. Blair, Sales Manager, Norton Motors (1978) Limited, Lynn Lane, Shenstone, Lichfield, Staffordshire WS14OEA, England; Mr. G. K. Blair
Sales Manager
Norton Motors (1978) Limited
Lynn Lane
Shenstone
Lichfield
Staffordshire WS14OEA
England;

Dear Mr. Blair: This is in reply to your letter of March 5, 1982, asking whether proposed motorcycle taillamp assembly would comply with Motor Vehicle Safety Standard No. 108.; As you point out, the standard requires a minimum distance of 4 inche edge to edge between turn signal lamps and stop/tail lamps. Since you state that you cannot achieve this with your design, the lamp as currently designed would not be permitted by our standard. This will confirm the oral interpretation provided by Taylor Vinson of this office when you telephoned on March 22.; You will be interested to know that we are presently studying side an rear conspicuity of motorcycles. This research is being conducted by Ketron in Philadelphia, Pennsylvania, and the final report is expected in July 1982 should you wish to obtain a copy of it from us.; As you requested confidential treatment of your engineering drawing, w are returning it to you.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam3678

Open
Mr. T. J. Brown, Mohawk Rubber Company, Roanoke, VA 24017; Mr. T. J. Brown
Mohawk Rubber Company
Roanoke
VA 24017;

Dear Mr. Brown: This is in response to your March 28, 1983, letter to Roger Fairchil of this office, requesting confirmation of your understanding of the effective dates for the recent suspension of treadwear grading under this agency's Uniform Tire Quality Grading Standards.; Your understanding of the effective dates is correct. Tires produced i molds manufactured on or after August 8, 1983, must have the new grading format which excludes treadwear information. Tires produced in molds manufactured before that date may either use the new format as soon as feasible, to minimize the dissemination of misleading information with regard to tire treadwear.; With regard to labels, the requirement that such labels must contai information regarding treadwear grades was suspended effective February 7, 1983. The preamble to the final rule states that manufacturers will be permitted to exhaust inventories of labels which were in existence as of the date of the suspension. Thereafter, manufacturers should begin using labels without treadwear information.; If you have further questions on this matter, please feel free t contact us.; Sincerely, Frank Berndt, Chief Counsel

ID: aiam1365

Open
Irvin Jacobs, M.D., Corner Sterling & Machell Avenues, Dallas, Pennsylvania 18612; Irvin Jacobs
M.D.
Corner Sterling & Machell Avenues
Dallas
Pennsylvania 18612;

Dear Mr. Jacobs: This is in reply to your letter of November 21, 1973 to 'U.S. Bureau o Safety' expressing your view that 'the automobile industry should ... have some type of clutch to reverse action when the closing motion of the (power) window meets any resistance.'; I enclose a copy of Federal Motor Vehicle Safety Standard No. 11 *Power-operated Window Systems* which has applied to all passenger cars and multipurpose passenger vehicles with power windows manufactured since February 1, 1971. The objective of the standard is to minimize the likelihood of injury or death occurring when a person is caught between a closing window and its frame, channel, or seat. The NHTSA determined that the most cost-effective way to accomplish this objective was by prohibiting operation of power windows when the ignition key is either in the ignition 'off' position or removed. As you will see from the enclosure, consideration was given to mechanisms that would reverse the direction of the window.; We appreciate your interest in motor vehicle safety. Sincerely, Richard B. Dyson, Assistant Chief Counsel

ID: aiam1484

Open
Mr. Tatsuo Kato, Staff, Safety, Nissan Motor Company, Ltd., 560 Sylvan Avenue, Englewood Cliffs, NJ 07632; Mr. Tatsuo Kato
Staff
Safety
Nissan Motor Company
Ltd.
560 Sylvan Avenue
Englewood Cliffs
NJ 07632;

Dear Mr. Kato:#This is in reply to your letter of April 23, 1974 asking for an interpretation of Standard No. 101, as proposed in the *Federal Register* on September 27, 1973. You reference that portion of Paragraph S4.3.3 which states 'If illumination of controls and displays not listed in Paragraph S4.1 is provided, its intensity shall be variable in a manner that complies with this paragraph'.#The basic requirement of S4.3.3 is that 'A control shall be provided to adjust the intensity of control and display illumination. . . .' We interpret the basic requirement as applying to *all* control and display illumination, not just illumination of the minimum number of controls and displays specified in Tables I and II. Thus if the manufacturer chooses to provide illumination for *any* control or display, even those not related to safety such as the radio or clock, its intensity shall be variable in accordance with Paragraph S4.3.3.#Yours truly, Richard B. Dyson, Assistant Chief Counsel;

ID: aiam2425

Open
Mr. Richard B. Ansell, Anschelewitz, Barr, Ansell & Bonello, 513 Bangs Avenue, Asbury Park, NJ 07712; Mr. Richard B. Ansell
Anschelewitz
Barr
Ansell & Bonello
513 Bangs Avenue
Asbury Park
NJ 07712;

Dear Mr. Ansell: This responds to your September 8, 1976, question whether the window of recreational vehicles' qualify as secondary means of egress' and what Federal requirements would apply to them if they do so qualify.; The only Federal requirement for the provision of emergency exits appl to buses (Standard No. 217, *Bus Window Retention and Release*, 49 CFR 571.217 (copy enclosed)). Bus' is defined by our regulations to mean a motor vehicle with motive power, except a trailer, designed for carrying more than 10 persons (49 CFR 571.3). Thus, Standard No. 217 would apply to the vehicle you describe if it is designed to carry more than 10 persons (including the driver) while the vehicle is in motion.; The standard does not use the term secondary means of egress' bu specifies a minimum area of unobstructed opening that may be provided by several means (*e.g.*, emergency door, push-out window').; Sincerely, Frank A. Berndt, Acting Chief Counsel

ID: aiam2717

Open
Mr. Paul Bennett, Utility Trailer Manufacturing Co., P.O. Box 1299, City of Industry, CA 91749; Mr. Paul Bennett
Utility Trailer Manufacturing Co.
P.O. Box 1299
City of Industry
CA 91749;

Dear Mr. Bennett: This responds to Utility Trailer Manufacturing Company's October 6 1977, request for confirmation that the criteria for a bulk agricultural commodity trailer contained in S5.6 and S5.8 of Standard No. 121, *Air Brake Systems*, can be met by a trailer that does not accommodate 'slip-in bottom dump' bulk harvest tubs as well as the 'deck type' harvest tubs used for tomatoe (sic) harvesting. From your description, it is assumed for the purposes of this interpretation that the trailers in question do conform to the criteria in the standard for maximum length and an air line and reservoir arrangement that minimize field damage.; The criterion of 'skeletal construction that accommodates harves containers' can be met by a design that accommodates mounting of deck type bulk harvest tubs by means of removable flooring, whether or not the removal of flooring also permits the mounting of 'slip-in bottom' bulk harvest tubs.; Sincerely, Joseph J. Levin, Jr., Chief Counsel

ID: aiam0291

Open
Mr. Y. Nakajima, Manager, Engineering Department, Koito Manufacturing Co., Ltd., 4-8-3, Takanawa, Minato-Ku, Tokyo, 108 Japan,; Mr. Y. Nakajima
Manager
Engineering Department
Koito Manufacturing Co.
Ltd.
4-8-3
Takanawa
Minato-Ku
Tokyo
108 Japan
;

Dear Mr. Nakajima: This is in reply to your letter of January 22, 1971, to Mr. Charles A Baker of this Office concerning questions on paragraph S4.1.1.7 of Federal Motor Vehicle Safety Standard No. 108.; 'Red' was inadvertently included in paragraph S4.1.1.7 of the amendmen to Standard No. 108 published on October 31, 1970. It is anticipated that this paragraph will be further amended in the near future by changing '...requirements for Class A red turn signal lamps...' to '...requirements for Class A turn signal lamps...'; The answers to your questions are therefore as follows: >>>1. Amber turn signal lamps shall conform to the minimum candlepowe requirements for Class A amber as specified in Table 2 of SAE J575d.; 2. There is no maximum candlepower requirement for amber front tur signal lamps.<<<; Sincerely, Roger H. Compton, Director, Office of Operating Systems Motor Vehicle Programs;

ID: nht88-3.4

Open

TYPE: INTERPRETATION-NHTSA

DATE: 08/12/88

FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TO: Anonymous (Confidential)

TITLE: NONE

TEXT: This is in reply to your letters of December 3, 1987, January 19, 1988, and April 4, 1988 (to Taylor Vinson of this Office), asking whether a device of your invention complies with all applicable Federal regulations. You have also requested information on how to petition for adoption of this device as mandated equipment on new motor vehicles. We regret the delay in responding to your letter.

You have requested confidentiality of this matter to the extent permissible. As Mr. Donaldson of this Office explained to you by phone on January 14, our practice is to make available for public perusal copies of all agency interpretations, but not nece ssarily the correspondence that occasioned the interpretation, and, upon request, to delete from the interpretation the name and address and other data that might identify the person requesting the interpretation. You have assented to the withholding of your name and address in your letter of January 19. In that letter you requested withholding the drawings you enclosed on December 3. We shall not attach them to the copy of this letter made publicly available (although they will be subject to review by agency personnel who review this letter before I have signed it, and may be subject to eventual disclosure under a Freedom of Information Act request). However, the device must be described to the extent necessary to allow a reader to understand just what the opinion covers.

Your device is a horizontal bar of lamps mounted inside the rear window of a passenger car consisting of the center highmounted stop lamp in the center, flanked by back up lamps, which are themselves flanked by left and right turn lamps. Each of the fiv e lamps would have a lens area approximately 6" wide and 1 1/2 inches high.

The applicable Federal law and regulation is the National Traffic and Motor Vehicle Safety Act and Federal Motor Vehicle Safety Standard No. 108 Lamps, Reflective Devices, and Associated Equipment. With respect to acceptability of your device as an ite m of original equipment, for purposes of this interpretation we assume that the device is intended to replace the standard center highmounted stoplamp, but only to supplement

2 the backup and turn signal lamps. Your device appears permissible as an item of original equipment under Standard No. 108 provided that all requirements for the center highmounted stoplamp continue to be met. We call your specific attention to the fa ct that means must be provided to minimize reflections from the center lamp upon the rear window glazing that might be visible to the driver, either directly or indirectly in the rearview mirror. Supplementary original lighting equipment is permissible under Standard No. 108 as long as it does not impair the effectiveness of lighting equipment required by the standard. The certification by a manufacturer that its vehicle complies with Standard No. 108 would encompass a certification that there is no i mpairment by any supplemental lighting equipment. The vehicle manufacturer must also consider whether any device installed in a rear window affects compliance with the interior rearview mirror field of view requirements specified by Standard No. 111 Rea rview Mirrors, and if affirmative to provide a passenger side exterior mirror.

The Vehicle Safety Act covers safety related defects as well as motor vehicle safety standards, requiring notification of purchasers and remedy of safety related defects when they occur. Spillage of light upon the rear glazing could be considered as a s afety related defect, and, for this reason, means should be provided to minimize reflections upon the rear glazing from all lamps in the array, and not just the center lamp.

The applicable Federal law for aftermarket equipment is also the Vehicle Safety Act. It prohibits modifications by manufacturers, distributors, dealers, and motor vehicle repair businesses to vehicle if those modifications render inoperative in whole or in part equipment installed in accordance with a safety standard. Center highmounted lamps have been required as original equipment on new cars manufactured on or after September 1, 1985. Because of the potential for interfering with the effectiveness of the center lamp, we would regard removal of an original equipment center lamp and substitution of your device including its center lamp as rendering the center lamp partially inoperative within the meaning of the prohibition. However, if the modific ation is such that it can be done by the vehicle owner, the Act does not prohibit an owner from it. Further, the Act would not prohibit in any way the installation of your device on passenger cars manufactured before September 1, 1985. However, supplem entary lighting devices sold in the aftermarket are regulated by each State in which the device would be sold and used. Although we are not conversant with those laws, you may consult the American Association of Motor Vehicle Administrators, 4600 Wilson Boulevard, Arlington, Va. 22203 for an opinion.

You have also asked how this device could be mandated as original equipment on new passenger cars. Any interested person may petition the Administrator for an amendment of Standard No. 108. However, the Vehicle Safety Act requires the safety standards to be standards for motor vehicle performance, and, to the extent possible, the agency attempts to minimize standards expressed in terms of design. For the same reason, the agency does not normally propose adoption of proprietary designs. As one of the requirements of a petition for rulemaking is that it contain the name and address of the petitioner, it might not be possible

3 to afford the same degree of confidentiality to a petition that it is to a request for an interpretation.

Your letter of April 4 asks a slightly different question on the subject of what is allowed to be viewed by other motorists in or around the rear window, with specific reference to turn signals, backup lamps, and hazard warning signals. The relevant port ions of Standard No. 108 are those relating to mounting height. The maximum mounting height of 83 inches allowed for turn signals (which commonly also serve as hazard warning signals) is unlikely to be exceeded by turn signals mounted in the rear window area. There is no maximum restriction on the mounting height of backup lamps but we do have performance criteria which must be met in order to ensure that they can satisfy their intended function of providing illumination behind the vehicle. Finally, y ou should realize that it is incorrect to refer to your device as a "third tail light assembly." A taillamp is a specific rear lamp required by Standard No. 108, and one which you have not incorporated into your assembly.

I hope that this answers your questions. As you requested in a phone call to Taylor Vinson the other day, we are returning the originals of your correspondence.

Enclosures

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.

Go to top of page