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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 9361 - 9370 of 16510
Interpretations Date
 search results table

ID: nht89-1.100

Open

TYPE: INTERPRETATION-NHTSA

DATE: 05/17/89

FROM: ROD WILLAREDT -- DIAMOND CROSS LIGHTS

TO: TAYLOR VINSON -- NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 06/19/89 FROM STEPHEN P. WOOD -- NHTSA TO ROD WILLAREDT; REDBOOK A33[B][2]; STANDARD 108; LETTER DATED 04/18/88 FROM ERIKA Z. JONES -- NHTSA TO WAYNE APPLE; STANDARD 108; LETTER DATED 02/19/88 FROM ERIKA Z. JONES -- NHTSA TO CHARLES WILSON -- CONGRESS; STANDARD 108; LETTER DATED 07/11/88 FROM ERIKA Z. JONES -- NHTSA TO WILLIAM J. STEPHENSON; STANDARD 108

TEXT: Dear Mr. Vinson,

In reference of our phone conversation of early May, I would appreciate a letter of confirmation reguarding the D.O.T. codes and regulations concerning Diamond Cross's Safety Light.

As I mentioned to you on the phone, upon my personal visitation to Washington over a year ago, I received an oral approval of the Chief Council that our safety light was not in any violation of codes or regulations. We are presently at the stage of marketing this product and have been advised that confirmation of such D.O.T. approval should be of record on file.

The safety light itself shows left/right directional signals and when the caution light/emergency light appears, the formation of such lights indicates a diamond. Please note again, this safety light is an "auxiliary" truch light and does not replace any origional equipment.

As time is of essence to us, I will give you a call later today to confirm receival and confirmation of written approval to follow. Thank you for your time and readiness concerning this matter.

Sincerely yours,

DC (trademark) Lights

(c) -- 1988 P.O. Box 3696 Rapid City, SD 57709 (605) 341-2331 Rod

DIAMOND CROSS(trademark), INC.

Truck Safety Light (DIAGRAM OMITTED)

SEE ILLUSTRATION ON ORIGINAL * Auxiliary truck light.

* Increase rear end visibility by 100%

* Gives an extra turn signal that is a safety feature.

* Gives an extra caution signal in a diamond shape

ID: nht89-1.11

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/01/89

FROM: LES SCHREINER -- FRESIA ENGINEERING INC.

TO: CHIEF COUNCIL, NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 04/03/89 FROM ERIKA Z. JONES -- NHTSA, TO LESS SCHREINER, REDBOOK A33 (2), VSA 102 (3)

TEXT: Gentlemen:

Our company is a wholly owned subsidiary of an Italian corporation wishing to market its product in the United States. Future plans include U.S. manufacture as demand increases. The potential market for our products is both off road cliental (e.g., air ports) and public road organizations such as city, county, and state highway departments. Plans also include bidding on contract from various U.S. Government and military branches. It is for this reason we wish to clarify whether our products fall unde r Title 49, Section 571 compliance requirements or are exempt under the act.

Technical data on our equipment is included for your review, however, should additional information be required, we would be pleased to provide same. Fresia would also be interested in any approval procedure or testing process NHTSA would administer tha t would establish our equipment on any QPL (Qualified Product List) program.

We appreciate your time and consideration and look forward to your response.

Best regards,

(Enclosure omitted.)

ID: nht89-1.12

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/03/89

FROM: KENNETH E. MADDEN -- RESEARCH ASSOCIATE UNIVERSITY OF IOWA

TO: ERIKA JONES -- CHIEF COUNSEL NHTSA

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 03/24/89 FROM ERIKA Z. JONES -- NHTSA TO KEITH E. MADDEN, REDBOOK A33 (2), CUSTOM REGULATIONS; LETTER DATED 12/04/87 FROM PAUL L. PETERSCHMIDT TO GEORGE PARKER

TEXT: Dear Ms. Jones:

Over a year ago we sent the inclosed coorespondence to DOT detailing the test plans for the importation and testing of three neat ethanol pickups under DOT Form HS 7, Item 7. We now have progressed to ordering the vehicles. Auto-Latino, Sao Paulo, Br azil routinely exports gas and diesel vehicles into Baltimore, Md. but has never exported the ethanol vehicle. Mr. Walter D'Alesandro, Export Manager Ford Brazil, specifically requests some form of official acquiescence to this procedure before producti on and shipment of the vehicles.

We have requested this assurance from DOT and have been referred to your office in phone conversations with Mr. Clive Van Orden and Mr. Taylor Vincent. I appreciate the fact that Mr. D'Alesandro is not subject to US jurisdiction, but he is concerned a bout repurcussions if things are not in order. A letter from your agency to the University of Iowa stating that there are no legal or administrative roadblocks to this importation would be appreciated.

We would appreciate your earliest accomodation to this matter since we must hold off ordering these vehicles until some assurance can be sent to Sao Paulo, Brazil. If there is any question regarding the test plan or this request please contact me at (319) 335-1415 or 1400. Thank you.

Sincerely,

ID: nht89-1.13

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/03/89

FROM: ROBERT C. CRAIG -- QUALITY CONTROL MANAGER COSCO INC

TO: GEORGE L. PARKER -- DIRECTOR OFFICE OF DEFECTS INVESTIGATION - ENFORCEMENT U.S. DEPARTMENT OF TRANSPORTATION N.H.T.S.A.

TITLE: 49 CFR 571.213; STANDARD NO. 213 CHILD RESTRAINT SYSTEMS. @ 5.5.1. LABELING; RULING: INCORPORATE THE METRIC SYSTEM OF MEASUREMENTS INTO THE STANDARD.

ATTACHMT: ATTACHED TO LETTER DATED 04/17/89 FROM ERIKA Z. JONES -- NHTSA TO ROBERT C. CRAIG, REDBOOK A33(2), STANDARD 213

TEXT: Dear Mr. Parker:

Cosco, Inc. has been purchased by Dorel Industries, Inc. of Montreal, Quebec. With the purchase, Cosco is making child restraints for the United States and Canada. Canada requires the metric system of measurements on all child restraint labels and instr uctions. To meet the Canadian requirement, Cosco wishes to incorporate the metric system of measurements on their present labels and instructions.

Example: "This child restraint is designed for use only by children who weigh 40 pounds (18 kg) or less and are 40 inches (1 M) or less in height."

Cosco requests permission to include metric equivalents on all Cosco child restraints and confirmation that use of metric equivalents as described above is in conformance with the requirements of FMVSS 213.

Thanking you in advance for your consideration of the above. If there are any questions or information needed, please contact me directly.

Sincerely,

ID: nht89-1.14

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/03/89

FROM: STEVEN P. ELLIOT -- CITY OF SPARKS ATTORNEY

TO: HARRY REID -- UNITED STATES SENATOR

TITLE: AUTHORIZATION TO DISCONNECT AUTOMOBILE AIR BAGS

ATTACHMT: ATTACHED TO LETTER DATED 05/25/89 FROM STEPHEN P. WOOD -- NHTSA TO HARRY REID -- SENATE; REDBOOK A33 [4]; VSA 108 [A] [2] [A]; STANDARD 208; LETTER DATED 03/08/89 FROM PATRICIA KLINGER WATHEN -- DOT TO HARRY REID -- SENATE; LETTER DATED 02/23/8 9 FROM HARRY REID -- SENATE TO DOT; REPORT FROM DAVID J. ROMEO AND JOHN B. MORRIS, DRIVER AIR BAG POLICE FLEET DEMONSTRATION PROGRAM A 24 MONTH PROGRESS REPORT AT EXPERIMENTAL SAFETY VEHICLE CONFERENCE OXFORD, ENGLAND, JULY 1-5, 1985; RESEARCH NOTES ON C RASH EXPERIENCE OF GOVERNMENT SPONSORED AIR BAG VEHICLES THROUGH 03/31/89, FROM VERNON ROBERTS

TEXT: Dear Senator Reid:

The City of Sparks Police Department just received delivery of six Plymouth Grand Fury police patrol vehicles. These automobiles are equipped with air bags and have a sticker on the dashboard stating that it is a violation of federal law to disconnec t the air bag. Since the Police Department is finding it difficult to engage in normal police activities with the air bags installed as they are and the City of Sparks does not want to violate a federal law, we are hoping you will help us obtain permiss ion to disconnect the air bags in our new vehicles.

The Sparks Police Department is finding it difficult to work with the air bags because police cars are often required to push disabled vehicles out of the travel lanes of a street or highway. The air bags are activated when the front bumper of the pa trol car receives a certain amount of pressure. We believe that the pressure threshold will be reached when a patrol car bumper is used to push another vehicle. This is particularly so if the disabled vehicle has been damaged so that its wheels do not turn freely or if the vehicles bump together due to an uneven surface. We have been informed that air bags are not reusable, and the replacement cost for an air bag is approximately $ 700.00.

We believe the United States Department of Transportation can authorize the City of Sparks to disconnect the air bags permanently or temporarily. We would like to receive authorization to disconnect the air bags on our police patrol vehicles so the v ehicles then can be safely and economically used to push disabled vehicles. Any assistance you can provide us in this matter will be greatly appreciated.

Sincerely yours,

ID: nht89-1.15

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/04/89

FROM: LEON E. PANETTA -- CONGRESS

TO: ERIKA JONES -- CHIEF COUNSEL NATL. HWY. TRAFFIC SAFETY ADMIN.

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 04/17/89 FROM ERIKA Z. JONES -- NHTSA TO LEON E. PANETTA, REDBOOK A33(2), STANDARD 111

TEXT: Dear Ms. Jones:

Recently one of my constituents contacted me about a matter which falls under your agency's jurisdiction. Specifically, Mr. Botelho, a professional driver, was concerned about the requirements for having a mirror on the right side of his vehicle. He wa nts to know whether there is a law requiring mirrors on the right side and if those mirrors must be made convex.

Mr. Botelho feels that it is important for mirrors to portray an accurate image and not cause an object to appear further away than they really are. In my constituent's opinion, the mirrors are hazardous and confusing.

I would appreciate your office clarifying this requirement and its applications to professional drivers in California. I would like further information on the background of this requirement and the reasons for its implementation.

I would appreciate your agency responding in writing to me directly.

I look forward to hearing from you soon.

Sincerely,

ID: nht89-1.16

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/06/89 EST

FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TO: LEONARD M. PERKINS

TITLE: NONE

ATTACHMT: LETTER DATED 09/07/88 FROM LEONARD M. PERKINS TO ROBERT BURNLEY -- DOT

TEXT: Dear Mr. Perkins:

Secretary Burnley has asked me to respond to your letter of September 7, 1988, with respect to your lighting device. In essence, this is a center high-mounted stop lamp, with turn signal lamps adjacent to it. You believe that high-mounted turn signals "joined with the rear window brake light should have a dramatic effect on rear and side collections", but you have been told that "this conception is at present illegal."

Paragraph S4.4 of Federal Motor Vehicle Safety Standard No. 108 states that "no high-mounted stop lamp shall be combined with any other lamp or reflective device." We interpret this as prohibiting lamps or reflective devices that share a single lens or c ompartment with the center highmounted lamp. Your device shows lamp adjacent to the center highmounted lamp but not combined with it. Therefore, your device is not prohibited by that paragraph of the standard if you wish to market this device as origina l equipment. The next question to ask is whether it impairs the effectiveness of required lighting equipment (paragraph S4.1.3), principally the center stoplamp. For example, if the yellow turn signals were too bright or if the color of the turn signal were red, these lamps might "impair the effectiveness" of the center stoplamp. However, this is a determination to be made, in the first instance, by the manufacturer of the vehicle who must certify compliance with Standard No. 108.

If you wish to sell your device in the aftermarket, it is acceptable under Federal law if its installation does not adversely affect the operation of motor vehicle equipment installed in accordance with a Federal motor vehicle safety standard so that the equipment would no longer comply with the standard. Assuming that the installation does not have this effect, the legality of installing or using such a device must then be determined according to the laws of any State in which a vehicle so equipped is registered or operated, and these auxiliary lamps must

comply with any State requirements. We cannot advise you on State laws. One source of advice is the American Association of Motor Vehicle Administrators, 4600 Wilson Blvd., Arlington, Va. 22203.

Sincerely,

ID: nht89-1.17

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/09/89

FROM: J. JAMES EXON -- SENATE

TO: CONGRESSIONAL LIAISON DEPT. OF TRANSPORTATION

TITLE: NONE

ATTACHMT: ATTACHED TO LETTER DATED 03/17/89 FROM ERIKA Z. JONES TO J. JAMES EXON -- SENATE, REDBOOK A33; STANDARD 108, VSA 108(A)(1)(A), VSA 108(A)(2)(A), PART 567.7; LETTER DATED 01/26/89 FROM RON MOXHAM TO J. JAMES EXON; LETTER DATED 09/25/88 FROM RON MOXHAM TO ERIKA Z. JONES -- NHTSA

TEXT: Dear Sir:

I am enclosing a letter from:

Ron Moxham

Box 65

Chester, Nebraska 68327

whose problem appears to fall within your jurisdiction.

I would appreciate any information which will enable me to respond to my constituent's inquiry. Please return the enclosed correspondence with your report to:

Senator J. James Exon

287 Federal Building

100 Centennial Mall North

Lincoln, NE 68508

Cordially,

Enclosure

ID: nht89-1.18

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/10/89

FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TO: J. W. LAWRENCE -- MANAGER COMPLIANCE VOLVO GM HEAVY TRUCK CORPORATION

TITLE: NONE

ATTACHMT: LETTER DATED 10/05/88 FROM J. W. LAWRENCE TO ERIKA Z. JONES -- NHTSA, REQUEST FOR INTERPRETATION FMVSS 124 ACCELERATOR CONTROL SYSTEMS, OCC 2650; LETTER DATED 03/17/88 FROM ERIKA Z. JONES -- NHTSA TO LEON STEENBOCK

TEXT: Dear Mr. Lawrence:

This is a response to your letter of October 5, 1988, asking this agency to "reconsider and rescind" an interpretation of Standard 124, Accelerator Control Systems (49 CFR @ 571.124). The interpretation which was the subject of your request was addresse d to Mr. Leon Steenbock and dated March 17, 1988. Mr. Steenbock asked whether it is permissible under Standard 124 to install a locking hand throttle control in a new motor vehicle. In our response to Mr. Steenbock, we stated that while nothing in the Standard prohibits installing a hand-throttle control in a new vehicle, "'locking hand throttle controls' are expressly prohibited by Standard 124."

In your letter, you stated that most (and perhaps all) heavy truck manufacturers install hand throttles for engine warm-up, extended idle periods; and for vocational applications such as pumping, compacting, and mixing. You also stated that your company installs only locking hand throttle controls and that these locking hand throttle controls hold the driver-selected engine idle speed until such time as the driver selects a new idle speed, or disengages the throttle.

In support of your position that the letter to Mr. Steenbock was incorrect, you referred to the agency's response to petitions for reconsideration of Standard 124. NHTSA's response to requests that special provisions be made for hand throttles was as fo llows:

Mack and Alfa Romeo petitioned that "hand-throttles" and throttle positioners be specifically excluded from the definition of "idle position." Petitioners stated that in the event such a device is used a return to the present throttle position occurs upon release of the driver-operated accelerator control system. This request is granted. If a driver choose to raise the lowest engine speed

threshold by the use of a throttle positioning device, the throttle should return to that new position within the same time requirements specified in section S5.3. Accordingly, the NHTSA is amending the definition of "idle position" to provide for the u se of throttle positioners. (37 FR 20033, September 23, 1972.)

In accordance with this stated intent, the definition of "idle position" in S4.1 of Standard 124 was amended to read:

(T)he position of the throttle that will provide the lowest engine speed for existing conditions according to the manufacturers' recommendations. These conditions include, but are not limited to, engine speed adjustments for cold engine, air conditio ning equipment, and emission control equipment, and the use of throttle setting devices.

Because of this language, we agree with your position that Standard 124 permits the installation of hand throttles, including locking hand throttle controls, provided that the vehicle's engine returns to the lowest engine speed threshold as adjusted by u se of the hand throttle within the time and under the conditions set forth in S5 of Standard 124. To the extent that our March 17, 1988 letter is inconsistent with this interpretation, it is incorrect.

I hope you find this information helpful. If you have further questions, please call Joan F. Tilghman of my staff at (202) 366-2992.

Sincerely,

ID: nht89-1.19

Open

TYPE: INTERPRETATION-NHTSA

DATE: 02/10/89

FROM: ROLF DUERR -- NOITH TRANSMISSIONS PROJECT ENGINEER

TO: U.S. DEPARTMENT OF TRANSPORTATION OFFICE OF CHIEF COUNCIL

TITLE: DOT APPROVAL OF SWAGELOK FITTING

ATTACHMT: LETTER DATED 08/23/89 FROM STEPHEN P. WOOD -- NHTSA TO ROLF DUERR -- VOITH TRANSMISSIONS; REDBOOK A34[2]; FMVSS 106

TEXT: To Whom It May Concern:

Enclosed, please find the fitting used on our product, the Voith VHBK-120 Driveline Brake Retarder. We are a European manufacturer of brake retarders and wish to make our product more adaptable to the American market. We are doing this by converting ou r metric air fittings to DOT approved fittings. Most of the air fittings we required were offered by Parker. The enclosed swagelok fitting will replace the enclosed DIN metric fitting as a positionable 90 degrees elbow.

Swagelok, as you may know, has no DOT designation standard on the fitting. Thus your approval is theoretically needed if it is attached to the air braking system of a truck. In our case, the air supply line to the retarder is tapped off of the auxiliar y air brake tank/system. Attached you will find technical specs on this swagelok fitting which we would like to use. I have also enclosed some literature on our product. Your prompt response will be greatly appreciated.

Regards,

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.