Pasar al contenido principal

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 8731 - 8740 of 16514
Interpretations Date
 search results table

ID: nht88-2.48

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/10/88

FROM: T. BAILEY -- LEGISLATION ENGINEER, INTERNATIONAL AUTOMOTIVE DESIGN

TO: NHTSA

TITLE: FMVSS 104 Windshield WIPING & WASHING SYTEMS

ATTACHMT: MEMO DATED 11-3-88, TO T.P. BAILEY, FROM ERIKA Z. JONES, STD. 104

TEXT: As an automotive design consultancy we need a clear understanding of this Standard, particularly the requirements of paragraph S4.1.2, Wiped Area. We have a problem with this and would appreciate some advice.

Firstly, can you confirm this paragraph is only applicable to passenger cars.

Secondly, the hypothetical results for a windscreen are shown on attachment 1. In this, Area A on one side extends to the DLO, on the other, overlaps it. (The DLO is taken to start at the inner edge of the obscuration band). As drawn, the correct perce ntage wiped area is still achieved. Should Area A be wholly:-

1. On exterior surface of glass, inside a perimeter line drawn one inch from edge of daylight opening.

2. On exterior surface of glass, inside the DLO.

3. On exterior surface of glass (ie. whole surface visible from outside vehicle including the obscuration band).

4. On total exterior surface of glass (ie. including the part normally hidden under trim and mouldings).

Thank you for your attention. I look forward to hearing from you.

See Illumtation on original

ID: nht88-2.49

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/10/88

FROM: A. J. ACKLEY -- MARTEK CORP.

TO: ERICA Z. JONES, CHIEF COUNSEL NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 12/08/88 FROM ERIKA Z JONES TO A J ACKLEY; REDBOOK A33, STANDARD 125; LETTER DATED 05/26/88 FROM A. J. ACKLEY TO JOAN TILLGHAM, OCC - 2096

TEXT: Dear Ms. Jones:

We are in the process of submitting a proposal to an account utilizing the red safety triangle. All of the elements of the device will follow the standards as set by the D.O.C. What we propose is using their logo in the center - see drawing. This woul d revolve (to eliminate a windshield) and add to the reflective quality of the device.

Do you see any legal problem with the concept?

Thank you.

ENCLOSURE

ID: nht88-2.5

Open

TYPE: INTERPRETATION-NHTSA

DATE: 04/21/88

FROM: JUANITA P. DAVISON

TO: DEPARTMENT OF TRANSPORTATION VEHICLE CRASH EMERGENCY MANAGEMENT

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 03/22/89 FROM ERIKA Z. JONES -- HNTSA TO JUANITA P. DAVISON, REDBOOK A33(2), STANDARD 208

TEXT: Please advise me to whom I can make some input about the automatic type seat belts. I have a 1987 Toyota and have also seen this type seat belt used in Ford makes.

Please tell me for what purpose this design has been used. Is it to meet some safety regulation? Or is it some gimmick of the auto manufactuer?

This belt is a nuisance and most inconvenient. A person is not fully belted unless the lap belt is also pulled in place. How much simpler to make one move accomplish the process of being fully belted.

This shoulder belt takes away the roominess of the front. It is in the way when getting in the car with a handbag or briefcase or package which needs to be placed elsewhere in the car. I wear glasses on a chain and I have to always hold this out of the way when the shoulder belt in in position. Passengers not familiar with the action are startled and confused by it. To disengage the belt after stopping the motor and just sitting in the car, the door has to be opened. This shoulder belt requires a sp ecial unlocking mechanism in case of emergency after impact. What if that is damaged during a collision. It is much more complicated than the push button used to release the lap belt (and combined lap and shoulder belts in other cars).

This is a travesty imposed on the ones who were not aware of the inconvenience and the fallacy of "automatic seat belts". I still have to buckle the lap belt and then be ready for the shoulder belt to rivet in place when the motor is turned on. The rev erse process when leaving the car. There is so much lost motion besides all the inconvenience just fr the sake of having a shoulder belt forceably used. Of course all I have to do is take the shoulder belt and lift it back over my head if I don't want to use it while driving. But I do want to be fully belted and would like the one step method. Can I legally disengage the motorized mechanism with the shoulder belt in place so that I can just lift it over my head? This would eliminate some of the dra wbacks.

Juanita P. Davison

(P.S.) I have also been told it is not safe to wear a shoulder belt without the lap belt, because of possibility of choking!

ID: nht88-2.50

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/16/88

FROM: DOUGLAS H. BOSCO -- MEMBER OF CONGRESS

TO: ERIKA JONES -- NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 08/19/88 TO DOUGLAS H BOSCO, FROM ERIKA Z JONES, REDBOOK A32 (2) STANDARD 108; LETTER DATED 08/03/87 TO DOUGLAS H. BOSCO FROM ERIKA Z. JONES; LETTER DATED 06/09/88 TO JERRY K YOST FROM L.F ROLLIN; LETTER DATED 03/28/88 TO C-MORE-LITE JERRYS SERVICE FROM DON O. HORNING RE TEST REPORT NO 92606; 1988 LETTER TO ERIKA Z. JONES FROM JERRY'S SERVICE

TEXT: Dear Erika:

You may recall that I corresponded with you last August regarding a head light device invented by my constituent, Mr. Jerry Yost. Several developments have taken place since that time, which may affect the status of Mr. Yost's C-More-Light invention.

Could you please review your earlier letter, the findings of Industrial Testing Laboratories, and the letter from the California Highway Patrol (all enclosed), and let me know what, if any, steps Mr. Yoste needs to take to legally market this device? Thank you very much for your prompt attention to this request.

Cordially,

ID: nht88-2.51

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/17/88 EST

FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA

TO: ROBERT CUZZI -- BREDA TRANSPORTATION, INC.

TITLE: NONE

ATTACHMT: MEMO DATED 12-9-87, FROM ROBERT CUZZI, TO ERIKA Z. JONES, RE: 020-1287

TEXT: This responds to your letter asking whether buses with a gross vehicle weight rating (GVWR) greater than 10,000 pounds are excluded from coverage under Federal Motor Vehicle Safety Standard No. 301, Fuel System Integrity. I regret the delay in respondin g to your letter.

The answer to your question is yes. Safety Standard No. 301 applies to new passenger cars, multipurpose passenger vehicles, trucks, and buses having a GVWR of 10,000 pounds or less and to all new school buses. The buses you manufacture for sale as muni cipal transit buses are excluded from Standard No. 301 because their GVWR is greater than the 10,000 pound limit established for the standard.

You asked also whether there are any other Federal standards that might apply to the fuel tanks on your transit buses. I have forwarded a copy of your letter to the Federal Highway Administration (FHWA) and the Urban Mass Transit Administration (UMTA) f or their direct reply as to the applicability of any FHWA or UMTA regulations to your transit vehicles. You might also contact the Environmental Protection Agency (EPA) to see whether that agency has any requirements affecting the fuel tanks on your bus es. The general telephone number for the EPA is (202) 382-2090.

ID: nht88-2.52

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/20/88

FROM: BYUNG M. SOH -- TARGET MARKETING SYSTEMS, INC, MARKETING DIRECTOR

TO: OFFICE OF CHIEF COUNSEL, NHTSA

TITLE: DOT RULING OR OPINION

ATTACHMT: ATTACHED TO LETTER DATED 9-13-88 TO BYUNG M. SOH FROM ERIKAZ. JONES

TEXT: Please find in enclosuree photocopies pertaining to informations on two devices which we intend to import to U.S.A. Even though these are not well written, I hope that the copies contain enough informations with which you could give us your opinion whet her these devices require approvals from D.O.T.

These are 1. Logical beam: foglight converter 2. C.L.S. system: head-lamp intensity modulator

These devices do not require to change existing lighting devices.

We believe that these devices enhance road safety.

If you require further information, we can be reached at (312)-673-7333 or by fax. (312)-673-7356.

Thank you.

ENC: 1 one set of photocopies of 'logical beam' and 'C.L.S. Systems'

ID: nht88-2.53

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/20/88

FROM: LEWIS S. BUCHANAN -- NHTSA DRIVER CONTROL PROGRAMS BRANCH OFFICE OF ALCOHOL & STATE PROGRAMS TRAFFIC SAFETY PROGRAMS

TO: LARRY P. EGLEY

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 08/09/89 FROM STEPHEN P. WOOD -- NHTSA TO LARRY P. EGLEY; REDBOOK A33 [2]; STANDARD 108; LETTER DATED 01/17/89 FROM LARRY P. EGLEY TO KATHLEEN DEMETER -- NHTSA; OCC 3028; LETTER DATED 05/23/89 FROM LARRY P. EGLEY TO KAT HLEEN DEMETER -- NHTSA; LETTER DATED 09/10/88 FROM LARRY P. EGLEY TO KATHLEEN DEMETER -- NHTSA; OCC 2530; REPORT DATED 09/10/88 FROM LARRY P. EGLEY, REQUEST FOR EVALUATION / INTERPRETATION OF PROPOSED INVENTION SUDDEN STOP FLASHER [SSF]; REPORT DATED 09/ 07/88 FROM LARRY P. EGLEY, AN APPEAL FOR VARIANT INTERPRETATION OF NHTSA STANDARDS AS THEY RELATE TO BRAKE LIGHTS AND THE SUDDEN STOP FLASHER [SSF]; LETTER DATED 07/13/88 FROM KATHLEEN DEMETER -- NHTSA TO LARRY P. EGLEY; LETTER DATED 06/23/88 FROM LARRY P. EGLEY TO RALPH HITCHCOCK -- NHTSA; OCC 2256; LETTER DATED 06/09/88 FROM LARRY P. EGLEY TO LEWIS BUCHANAN

TEXT: Dear Mr. Egley:

This is in reply to your letter to me regarding your Sudden Stop Flasher.

I do not work in the section of the National Highway Traffic Safety Administration which could appropriately respond to your question. Therefore, I have forwarded your letter to Mr. Ralph Hitchcock, Director, Office of Vehicle Safety Standards with a re quest that his office respond to you. I am certain you will be hearing from someone about your inquiry in the near future.

Thank you for your interest in preventing motor vehicle crashes.

Sincerely,

ID: nht88-2.54

Open

TYPE: INTERPRETATION-NHTSA

DATE: JUNE 22, 1988 EST

FROM: A. L. BRAGG -- LABORATORY MANAGER, TRUCK-LITE CO., INC.

TO: Z. TAYLOR VINSON -- SENIOR STAFF ATTY., NHTSA

TITLE: REQUEST FOR INTERPRETATION OF S4.1.16 AND S4.1.17 IN STANDARD NUMBER 108

ATTACHMT: LETTER DATED NOV. 3, 1988 (EST) TO A. L. BRAGG, LABORATORY MGR., TRUCK-LITE CO., INC., FROM ERIKA Z. JONES, CHIEF COUNSEL, NHTSA

TEXT: Our company currently manufactures several variations of stop, turn, and tail lamps that have a twelve square inch lens. Some particular models of this lamp also incorporate a ring of reflex reflector optics around the outside of the lens. It is our un derstanding that for the purposes of measuring the effective projected illuminated area of the lenses illuminated by an internal bulb, the reflex area (if present) must be subtracted from the total lens area, even though it may appear to transmit light. In the case of our particular lamps, we have a total of twelve square inches, from which we would subtract a four square inch area of reflex reflector which leaves eight square inches of effective projected illuminated lens area.

We note that the current FMVSS-108 document refers to SAE J586c, August 1970 for stop lamps and SAE J588e, September 1970 for turn signal lamps. A close reading of these standards indicates (to us at least) that for vehicles of eighty inches or more in width, an effective projected illuminated area of at least twelve square inches is required when two or more lamps are mounted closer together than twenty-two inches. We would further surmise that if a single stop/turn lamp were used or if two or mor e stop/turn lamps were used but that they were kept at least twenty-two inches or more apart, the twelve square inch rule would not be enforced and that eight square inches of effective projected illuminated area would be sufficient.

This matter is further complicated by the fact that in addition to the SAE standards just mentioned, there is a reference in S4.1.1.7 which seems to indicate that twelve square inches is required for vehicles ove eithty inches in overall width.

Our basic question is in reference to our combination lamp which has four square inches of reflector area and eight square inches of stop, tail and turn area. For vehicles over eighty inches wide can we advise our customers that these lamps may be us ed:

A) Singularly (that is one on each side of the vehicle in the rear) as a stop, turn, tail and reflex reflector?

B) In combination of two's or three's (on each side of the rear of the vehicle), provided that the lamps are separated by at least twenty-two inches?

We would be most grateful for your views and interpretation regarding the above. If we may offer any clarification, please feel free to contact us by letter or telephone.

ID: nht88-2.55

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/23/88

FROM: LARRY P. EGLEY

TO: RALPH HITCHCOCK -- OFFICE OF VEHICLE SAFETY STANDARDS NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 08/09/89 FROM STEPHEN P. WOOD -- NHTSA TO LARRY P. EGLEY; REDBOOK A33 [2]; STANDARD 108; LETTER DATED 01/17/89 FROM LARRY P. EGLEY TO KATHLEEN DEMETER -- NHTSA; OCC 3028; LETTER DATED 05/23/89 FROM LARRY P. EGLEY TO KAT HLEEN DEMETER -- NHTSA; LETTER DATED 09/10/88 FROM LARRY P. EGLEY TO KATHLEEN DEMETER -- NHTSA; OCC 2530; REPORT DATED 09/10/88 FROM LARRY P. EGLEY, REQUEST FOR EVALUATION / INTERPRETATION OF PROPOSED INVENTION SUDDEN STOP FLASHER [SSF]; REPORT DATED 09/ 07/88 FROM LARRY P. EGLEY, AN APPEAL FOR VARIANT INTERPRETATION OF NHTSA STANDARDS AS THEY RELATE TO BRAKE LIGHTS AND THE SUDDEN STOP FLASHER [SSF]; LETTER DATED 07/13/88 FROM KATHLEEN DEMETER -- NHTSA TO LARRY P. EGLEY; LETTER DATED 06/20/88 FROM LEWIS S. BUCHANAN -- EPA TO LARRY P. EGLEY; OCC 2199; LETTER DATED 06/09/88 FROM LARRY P. EGLEY TO LEWIS BUCHANAN

TEXT: Dear Mr. Hitchcock:

I was advised by Mr. Lewis Buchanan that he had forwarded my letter regarding my "Sudden Stop Flasher" (SSF) to you for response. In the event his letter did not reach you yet, I am enclosing another copy.

I should mention to you that I have conceived of several additional features which I did not mention in my letter to Mr. Buchanan because my intent was to communicate the basic concept only. However, I might briefly mention one of them. This the "Cr ash Lock-up Mode." This feature would cause the system to "lock-up" in the rapid warning flash sequence whenever an "impact-level" deceleration is encountered. When drivers have an accident, they are often confused and disoriented and fail to take measu res to protect themselves, such as turn on the hazard warning flashers. The Crash Lock-up feature would automatically send out a continuous warning when an actual crash occurs, thus possibly preventing yet another crash. Several years ago, I read of a 56-car pile up on a Florida Interstate on a very foggy night. I believe if only a few cars in that string of smashed up vehicles had this feature, that major disaster could have been significantly less severe. The Crash Lock-up would remain actuated un til the ignition switch was recycled.

Please accept my apologies for not addressing my original letter to you instead of Mr. Buchanan. Unfortunately, I was advised by the Kansas City Office that Mr. Buchanan would be the proper recipient.

Thank you very much for your attention.

ID: nht88-2.56

Open

TYPE: INTERPRETATION-NHTSA

DATE: 06/24/88 EST

FROM: ERIKA Z. JONES -- CHIEF COUNSEL, NHTSA

TO: CHARLEY ERICKSON -- CHARLEY'S OFF ROAD CENTER, INC.

TITLE: NONE

ATTACHMT: MEMO DATED 12-23-87, FROM CHARLEY ERICKSON, TO ERIKA JONES, OCC-1416

TEXT: This responds to your letter asking whether Safety Standard No. 302, Flammability of Interior Materials, applies to the "bikini sun shade," an accessory you wish to sell for both new and used open-body type passenger vehicles. I regret the delay in resp onding to your letter.

Generally speaking, items of motor vehicle equipment are not covered by Standard No. 302 and the bikini shade may be sold to vehicle owners for their installation in their own vehicles without regard to the product's conformance with the standard. Howev er, as explained below, Federal law places limits on the installation of the bikini shade by some commercial businesses.

Standard No. 302 establishes flammability requirements that must be met by new motor vehicles. The requirements apply to particular components within these vehicles, including shades. However, the requirements of the standard apply to a vehicle only un til its first purchase in good faith for purposes other than resale. They do not apply to shades manufactured for aftermarket sale and installation in a a vehicle after its first purchase. It would not violate Standard No. 302 for you to sell aftermark et bikini sun shades that do not comply with the standard.

However, the installation of the shades by certain parties other than vehicle owners could violate the National Traffic and Motor Vehicle Safety Act. Section 108(a) (2) (A) of the Act (copy enclosed) specifies: "No manufacturer, distributor, dealer, or motor vehicle repair business shall knowingly render inoperative ... any device or element of design installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard . . ." The f lammability resistance of the original vehicle is an element of design installed in a motor vehicle in compliance with Standard No. 302. That element of design would be rendered inoperative in violation of section 108(a) (2) (A) if a manufacturer, distr ibutor, dealer or motor vehicle repair business installed a bikini sun shade in a new vehicle and thereby caused that vehicle to fail to comply with Standard No. 302

There would also be a rendering inoperative when one of these parties installed the shade in a used vehicle if the shade would have caused the vehicle, when new, to fail to comply with the standard. Section 109 of the Act specifies a civil penalty of up to $ 1,000 for each violation of @108.

You should be aware also of an additional aspect of the Act. All manufacturers of motor vehicle equipment are subject to the provisions set forth in sections 151-159 of the Act concerning the recall and remedy of equipment with defects relating to motor vehicle safety. If it were determined that the bikini shade had a defect relating to motor vehicle safety, you as the shade manufacturer would have to notify all purchasers of the defect and either repair the shade so that the defect is removed, or rep lace the shade with an identical or reasonably equivalent product that does not contain a defect.

To summarize, there is a difference in the application of Standard No. 302 to vehicle equipment such as the bikini sun shade, depending on the identity of the person installing the shade in new and used motor vehicles. If the shade does not afford at le ast as good a level of flammability resistance as that specified by Standard No. 302, the shade cannot be installed in vehicles by any commercial business listed in @108(a) (2) (A) of the Safety Act. Shades that do not meet the standard's flammability r esistance requirements may legally be installed in vehicles by the owners of those vehicles. However, NHTSA discourages owners from installing any item of equipment that would degrade the safety performance of their vehicles. To repeat, you as the shad e manufacturer would still be obligated to recall and remedy shades that are determined to contain a defect relating to motor vehicle safety, even if those shades were installed by vehicle owners themselves.

I hope this information is helpful. Please contact us if you have further questions. ENCLOSURE

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.