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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 12801 - 12810 of 16490
Interpretations Date

ID: nht92-3.5

Open

DATE: 10/28/92

FROM: JANET TAYLOR -- MARKETING AND SALES MANAGER, A-PEX INTERNATIONAL CO., LTD.

TO: OFFICE OF THE CHIEF COUNCIL, NHTSA

TITLE: SUB: INQUIRY REGARDING THE STANDARD REQUIREMENTS FOR THE INSTALLATION OF THE TAP ROOT EQUIPMENT STAND INTO A MOTOR VEHICLE (CAR, VAN ETC.).; REF.: OUR PHONE CONVERSATION WITH MR. EDWARD JETTNER, 10/28/92.

ATTACHMT: ATTACHED TO LETTER DATED 12-28-92 FROM PAUL J. RICE TO JANET TAYLOR (A40; STD. 208)

TEXT: This letter serves to follow-up on the referenced phone conversation. We are a consulting firm that represents a manufacturer of a mechanical equipment stand, TAP ROOT EQUIPMENT STAND, that is installed into automobiles. Primarily, the use of the stand is for portable equipment such as laptop computers, facsimile machines, car phones, etc. Please refer to the attached drawing of the unit and installation instructions (with reference drawings, 3 pages).

This unit is intended to be sold to consumers after manufacture of a vehicle as additional equipment -OR- possibly this unit will be sold to fleet manufacturers as an accessory to the vehicle prior to reaching the showroom. At this time, the marketing efforts have been aimed to selling it to the consumer as additional equipment.

As indicated in the installation instructions, this is intended to be installed by "Joe Public" and it involves drilling a 1/2" hole in the floor pan of the vehicle.

Our inquiry to your office is the following: Is this product regulated is the USA? If YES . . . 1) How is it regulated? What are the specific requirements/standard #? 2) How may we obtain these requirements? 3) What type of paperwork, testing/evaluation is needed? 4) What agency would we contact for this matter? 5) What is the estimated cost and time for this type evaluation? 60 Can we evaluate and "self-certify" this product to these regulations? **

** Note: Our firm, A-PEX, is a consulting firm with a testing laboratory (do not have NRTL status) that specializes in assisting manufacturers in meeting product safety requirements (e.g. UL, FCC requirements.)

We would greatly appreciate your written response to the above matter as soon as possible. Our client is eager to meet the appropriate safety regulations and bring his evaluated product to market.

If you have any questions or comments to the enclosed, please do not hesitate to contact the undersigned.

ATTACHMENT TAP ROOT EQUIPMENT STAND INSTALLATION INSTRUCTIONS (TEXT AND PHOTOS OMITTED.)

ID: nht92-9.37

Open

DATE: January 28, 1992

FROM: Carl J. Clement -- Clement Associates

TO: Office of Chief Counsel, NHTSA

TITLE: None

ATTACHMT: Attached to letter dated 3/30/92 from Paul J. Rice to Carl J. Clement (A39; Std. 302; Std. 201)

TEXT:

I am in the process of inventing an automotive sun-visor which has the promise of improving upon the safety of currently used sun-visors. Within a week or so I shall have completed a mechanical protype which will serve as a means of testing electronics and optics. Enclosed is a patent disclosure which explains the device in greater detail.

I have been advised that, before proceeding further, I should research Federal and State agencies which have to do with regulations concerning automobiles, particularly automobile interiors. For example, are there regulations which would preclude the installation of an automatically-moving 3" high X 6" wide visor between the driver's eyes and the windshield?

I should appreciate your advice and a copy of any regulations with which I must comply, or which might be changed should the invention be viewed favorably by your or other government agencies.

ID: nht75-1.19

Open

DATE: 10/28/75

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Toyota Motor Sales, USA, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to Toyota's September 5, 1975, request for confirmation that the brake warning indicator labeling requirements in Standard No. 105-75, Hydraulic Brake Systems, permit the use of "PARK" and "SERVICE BRAKE" but prohibit the use of "PARK" and "BRAKE" as labeling for use on two indicator lamps, one signaling the condition of the parking brake system and the other signaling two or more functions of the service brake system. The relevant requirements of S5.3.5 of the standard state:

. . . . If a single common indicator is used, the lens shall be labeled "Brake." If separate indicator lamps are used for one or more of the various functions described in S5.3.1(a) to S5.3.1(d), the lens shall include the "Brake" and appropriate additional labeling (use "Brake Pressure," "Brake Fluid" for S5.3.1(a) and S5.3.1(b)) except that if a separate parking indicator lamp is provided, the single word "Park" may be used.

You are correct that S5.3.5 prohibits the use of one indicator labeled "PARK" with another indicator labeled "BRAKE". "PARK" may be used for a separate indicator of the parking brake condition, but only if the other indicator or indicators of brake system condition use the word "Brake" with appropriate additional labeling.

You asked if the designation "SERVICE BRAKE" would be a permissible label on an indicator separate from the "PARK" indicator. The designation would be permissible so long as it describes two or more of the conditions listed in S5.3.1(a), (b), or (c). You will note that S5.3.5 has specific labeling requirements for an indicator which signals only one condition in the case of 1(a), 1(b), and 1(d). In the case of S5.3.1(c), "SERVICE BRAKE" would not be appropriate labeling for the antilock function.

September 5, 1975

Dr. James B. Gregory, Administrator National Highway Traffic Safety Administration U. S. Department of Transportation 400 Seventh Street, S. W. Washington, D. C. 20590

Re: Interpretation of FMVSS No. 105-75, S5.3.5

Dear Dr. Gregory:

We wish to request clarification of our interpretation of S5.3.5, "Brake System Indicator Lamps," of FMVSS No. 105-75, "Hydraulic Brake Systems."

In S5.3.5 it reads as follows: ". . . If a single common indicator is used, the lens shall be labeled "Brake." If separate indicator lamps are used for one or more of the various functions described in S5.3.1(a) to S5.3.1(d), the lens shall include the word "Brake" and appropriate additional labeling (use "Brake Pressure," "Brake Fluid" for S5.3.1(a) and S5.3.1(b)) except that if a separate parking indicator lamp is provided, the single word "Park" may be used . . . ."

As we interpret it, this requirement does not prohibit the use of a separate indicator lamp for the parking brake labeled "Park" and one for the rest of the brake systems labeled "Service Brake." However, it does prohibit the simultaneous use of two separate indicator lamps labeled "Park" for the parking brake and "Brake" (without any additional labeling) for the other brake system functions, such as those described in S5.3.1(a) and S5.3.1(b).

We would appreciate your informing us of your opinion of our interpretation at your earliest convenience.

Very truly yours, TOYOTA MOTOR SALES, U.S.A., INC.

K. Nakajima Director/General Manager Factory Representative Office

KN:mc

ID: 23939.ztv

Open



    Mr. Michael Burgess
    Sales Manager
    Alliance Vehicle Systems
    2599 N. Orange Blossom Trail
    Kissimmee, FL 34744



    Dear Mr. Burgess:

    This is in reply to your undated letter to Taylor Vinson of this Office, which we received on January 22, 2002. As you may know, security precautions have caused a slowdown in the delivery of mail to Federal offices. If you sent your letter in the last two months of 2001, that is the reason for our delay in our responding to you.

    You have enclosed literature from Vantage Vehicle Group (VVG) and ask whether the group has "met all the criteria by your Department, and has received the proper approvals." This material consists of a cover letter dated August 28, 2001, addressed to "Turf & Golf Industry Dealers" and signed by "Jim Lester," and an information sheet on the vehicles that VVG is offering for sale. The vehicles about which you ask are identified as the "TruckALL," and the "VanGO." VVG identified the vehicles as "small utility trucks and vans," and stated that they are imported directly from Kia Motors of Korea. They are described as suitable "for golf course, utility work, and multi-person transportation."

    The same, or similar, Kia vehicles appear to have been the subject of our letter of May 4, 2000, to Ronald R. Shelton of Metro Motors Corporation (copy enclosed). We note, in passing, that Mr. Shelton's address is almost identical to yours (2595 vs. 2599 North Orange Blossom Trail). We sent a similar letter to Mr. Lester on June 26, 2001, a copy of which is enclosed.

    We note that VVG's material contains inaccuracies. It stated that "(1) Legal [emphasis in original] importers receive letters from each government agency granting import status for its vehicles to be sold for 'off road' only. Without such approval, fines and other penalties may apply. . . . VVG has met or exceeded all U.S. government requirements for its vehicles and is approved as an importer." This is not an accurate statement. We do not grant "import status" or "approve" persons or companies as importers of off-road vehicles. We provide interpretations upon request as to whether specific vehicles are, or appear to be, manufactured primarily for use on the public streets, roads, and highways (e.g., whether they are motor vehicles subject to our jurisdiction). If a vehicle was not manufactured primarily for use on the public roads, no Federal approval is required of the importer.

    VVG also stated that "U.S. DOT . . . regulations require that importers of vehicles used 'on road' in other countries, provide evidence that its vehicles have been 'speed limited' in a manner consistent with government requirements." It also stated that "The government requires us to limit the speed on our vehicles to a maximum of 25 mph, but the type of limiter is left up to each importer. VVG only installs a U.S. built . . . electronic speed limiter." These statements are incorrect. If a vehicle is used on the public roads in its country of origin, that is a factor that we consider in providing interpretations as to whether a vehicle would be a "motor vehicle" in the United States, even if the intent of the importer is to sell or use it in off-road applications. Speed capability plays little part in these interpretations. The relevant issue is whether the vehicle will be used on the U.S. public streets, roads, and highways, in which case vehicle speed capability may be a factor in determining whether the vehicle is a "motor vehicle" and a "low-speed motor vehicle."

    We are providing VVG with a copy of this letter.

    Sincerely,

    John Womack
    Acting Chief Counsel

    Enclosure
    cc: Vantage Vehicle Group
    ref:500
    d.3/6/02



2002

ID: nht94-4.26

Open

TYPE: INTERPRETATION-NHTSA

DATE: September 8, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Mary B. Falls, Esq. -- Sherrard & Roe, Nashville, TN

TITLE: NONE

ATTACHMT: Attached to letter dated 06/13/94 from Mary B. Falls to Office of General Counsel, NHTSA (OCC 10098)

TEXT: This responds to your request for an interpretation of whether, in replacing stolen vehicle identification number (VIN) plates as prescribed by Tennessee state law, your client, Nissan, would conform to this agency's requirements concerning VINs. The an swer is Nissan would not violate our requirements when it replaces the stolen "VIN plate." However, there may be other aspects of replacing stolen VIN plates that are under the U.S. Department of Justice's law enforcement jurisdiction.

By way of background, Standard No. 115, Vehicle identification number - basic requirements, requires manufacturers to assign a VIN to each motor vehicle, to simplify vehicle information retrieval and to increase the accuracy and efficiency of vehicle rec all campaigns. S4.5 of the standard specifies that VINs shall appear on a permanent part of the vehicle or on a separate label or plate, called the "VIN plate." S4.6 requires the VIN for passenger cars, multipurpose passenger vehicles and trucks of 10,00 0 lbs or less GVWR to be included in the passenger compartment, and manufacturers typically meet S4.6 by placing the VIN plate on the vehicle's dashboard.

Your letter explained that Nissan manufacturers cars and light trucks in Tennessee, and leases these vehicles. Sometimes, the VIN plate in the passenger compartment is stolen from the leased vehicle, but the vehicle is otherwise not tampered with. You stated that:

Section 55-5111 of Tennessee Code Annotated provides that it is a Class C misdemeanor for any person to buy, sell, offer for sale, or possess a motor vehicle from which the manufacturer's serial, engine from which the manufacturer's serial, engine, or transmission number or other distinguishing number or identification mark or number has been removed, defaced, covered, altered, or destroyed. In addition, @ 55-5-112 provides that the owner of an original engine, serial, engine, or transmission, or "o ther number or mark" may restore such number or mark pursuant to a permit issued by the Criminal Investigation Unit of the Tennessee Department of Safety.

You asked whether Nissan, the vehicle owner, would be "in full compliance" with NHTSA's regulations if Nissan replaced stolen VIN plates in accordance with Tennessee law. In response to your question, we note that Standard No. 115 applies only to new mo tor vehicles. In the event a VIN plate is stolen from a leased (i.e., used) motor vehicle, NHTSA has no authority to require that any party replace the VIN plate. Thus, under NHTSA's regulations, if the VIN plate is stolen from a used vehicle, Nissan, the owner, may use its discretion whether to replace the VIN plate.

However, please note that there could be other implications under Federal law about replacing stolen VIN plates. The U.S. Department of Justice has jurisdiction over stolen VIN plates as a law enforcement matter. Therefore, I suggest that you consult w ith the Justice Department about possible Federal law enforcement implications of replacing the stolen VIN plates.

I hope this information is helpful. If you have any further questions, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992.

ID: nht88-1.72

Open

TYPE: INTERPRETATION-NHTSA

DATE: 03/16/88

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: C.I. Nielsen -- Vice President, General Sales Manager, Wesbar Corporation

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. C. I. Nielsen Vice President General Sales Manager Wesbar Corporation P.O. BOX 577 West Bend, WI 53095

This is in reply to your letter of February 17, 1988, asking for an interpretation of paragraph S4.1.1.7 of Motor Vehicle Safety Standard No. 108, which applies to turn signal lamps. In pertinent part this section requires turn signal lamps for vehicles whose overall width is 80 inches or more to "have an effective projected luminous area not less than 12 square inches." Your design has a lens area of 12 square inches incorporating an integral Class A reflex reflector, and you have asked whether you may include the "illuminated (by the turn signal bulb) reflex reflector portion of the turn signal lens" in your calculation.

We assume from your letter that the light shines through the reflector when the turn signal is activated, and that the reflector is not opaque. In this instance, the reflector area may be included as part of "the effective projected luminous area" within the meaning of S4.1.1.7.

I hope that this answers your question.

Sincerely,

Erika Z. Jones Chief Counsel

February 17, 1988

Ms. Erika Jones, Chief Counsel-DOT Room 5219 NASSIf Building 400 7th Street, Southwest Washington, DC 20590

SUBJECT: REQUEST FOR COMPLIANCE INTERPRETATION 54.1.1.7

Dear Ms. Jones:

We are writing to you for clarification of 54.1.1.7 of FMVSS 108. Our request involves turn signal lamps on trailers 80-inches or more in width and, practically speaking, centers around the wording "shall have an effective project luminous area not less than 12 square inches".

Our design calls for a multifunction lens of 12 square inches, which incorporates an integral Class A reflex reflector. QUESTION: When the turn lamp is activated, may we include, for the square inch calculation, the illuminated (by the turn signal bulb) reflex reflector portion of the turn signal lens: We know we are allowed to optically combine two, or more, functions (except for the tail light with the clearance light function), therefore, we don't see this concept as the hurdle. Instead, we find the question lying with the definition of "effective projected luminous area".

Thank you for looking into this matter, Ms. Jones, and we look forward to receiving your written interpretation on the "effective projected luminous area".

Respectfully,

WESBAR CORPORATION

C.I. NIELSON III Vice President General Sales Manager

CIN:mm cc: J. Karrenbauer S. Johnston A. Cunningham DOT

(SEE ATTACHMENT...)

ID: nht94-1.12

Open

TYPE: Interpretation-NHTSA

DATE: January 7, 1994

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

TO: John G. Womack -- Acting Chief Counsel, NHTSA

TITLE: Request for Interpretation Regarding Combined Sun Visor Air Bag Caution Label and Utility Vehicle Label

ATTACHMT: Attached to letter dated 3/21/94 from John Womack to Dale E. Dawkins (A42; Redbook; Std. 208)

TEXT:

Chrysler Corporation requests that the NHTSA affirm an interpretation of MVSS 208-Occupant Crash Protection, that would permit the sun visor air bag caution label required in S4.5.1(b) to be combined with the utility vehicle information sticker required by 49 CFR Part 575.105. We believe that the messages of these labels are equally important to the operator of the vehicle, and that they can be effectively displayed together on a common label.

We are aware that General Motors Corporation and Ford Motor Company have submitted petitions for reconsideration of the final rule of Docket 74-14; Notice 82, which amends MVSS 208, in part, to require the sun visor label containing certain air bag cauti ons. Both companies ask that the agency further amend the air bag visor label requirement to permit the continued location of the utility vehicle label on the visor.

We support those petitions, and ask that the agency grant them and proceed with the proposed amendments. However, we ask that the agency also confirm that the information from both labels may not only appear on the same sun visor, but may be incorporate d into a single label on a given surface of the sun visor. In our opinion, the messages are of equal significance to the safe operation of the vehicle and deserve equal and simultaneous presentation to the driver. If the agency cannot affirm that posit ion within the existing regulation, please consider this request as a petition for rulemaking to that end.

If there are questions about this request, please address them to Howard Willson of my staff at (810) 370-8563.

ID: nht74-5.31

Open

DATE: 04/12/74

FROM: AUTHOR UNAVAILABLE; A. G. Detrick; NHTSA

TO: Harley-Davidson Motor Company Inc.

TITLE: FMVSR INTERPRETATION

TEXT: This is in reference to your defect notification campaigns NHTSA No. 73-0094, concerning fork lower brackets, and NHTSA No. 73-0215, concerning frame reinforcement and tail lamp wiring.

It has been brought to our attention that some dealers have not been able to obtain all the parts required for campaign 73-0094, and to a lesser degree, campaign 73-0215. Although it appears that Harley Davidson is attempting to provide parts as rapidly as production permits, this parts shortage has the unfortunate effect of tending to discourage owners from having their vehicles corrected. It is reasonable to assume that some owners may have abandoned their attempts to get their vehicles corrected after having been repeatedly told for several months that parts are not available.

Part 577.4 (49 CFR) of the Defect Reports Regulation requires that whom the manufacturer offers to repair the defect through his dealers without charge to the purchaser, the notification letter shall include the manufacturer's estimate of the day by which his dealers will be supplied with parts and instructions for correcting the defect. The letters which you have sent(Illegible Words) first purchasers did not contain a firm date for parts availability as required by Part 577, although they did imply that the necessary parts were available when ordered by a dealer. Since, in actuality, parts were not always available, it becomes necessary to inform owners of the date by which the necessary parts will be available.

It is therefore necessary that you revise the owner notification letters for both campaigns and include in each letter your estimate of the day by which dealers will be supplied with the necessary parts, as required by Part 577. Copies of both letters must be sent to this office and a copy of the applicable letter shall be sent to each owner who has not yet had his vehicle corrected.

If you desire further information, please contact Messrs. W. J. Reinhart or James Murray at this office (202) 426-2840.

ID: nht75-2.18

Open

DATE: 09/22/75

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Bridgestone Tire Company of America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: Please forgive the delay in responding to your letter of May 22, 1975, concerning truck tires which do nt conform to Federal Motor Vehicle Safety Standard No. 119 and which are intended for export to Middle Eastern and African countries.

49 CFR Part 571.7(d) and Section 108(b)(5) of the National Traffic and Motor Vehicle Safety Act of 1966, as amended, specify that no Federal Motor Vehicle Safety Standards apply to

a motor vehicle or item of motor vehicle equipment intended solely for export, and so labeled or tagged on the vehicle or item itself and on the outside of the container, if any, which is exported.

Therefore, tires which you manufacture for sale directly to a truck manufacturer who will mount them on trucks which will be driven directly to the port of export need not comply with Standard No. 119. When shipped to the truck manufacturer, the tires must bear a label or tag indicating intent to export. Such a label must also appear on the outside of the container, if any, in which the tires are shipped. A label need not remain on the tires after they have been mounted on the trucks, provided that the trucks bear similar labels.

Sincerely,

ATTACH.

BRIDGESTONE TIRE COMPANY OF AMERICA. INC.

May 22, 1975 Ref. No.: YT-926

Office of the Chief Counsel -- National Hwy. Traffic Safety Admin.

Subject: FMVSS No. 119

Dear Sir:

We have an inquiry on the following size tires to be equipped on new trucks for exporting to the Middle Eastern and African countries by a truck manufacturer: 400-500 1100-20 14PR 150-200 1100-22 14PR 400-500 1100-24 14PR

Since the tire usage condition in these countries is completely different from that of the U.S.A., we have been supplying specially designed tires to them which do not comply with the FMVSS No. 119.

Therefore, we would like to supply the same type of tires now being supplied to the Middle Eastern and African countries to the truck manufacturer strictly for export.

In such a case, will you adopt an exception to FMVSS No. 119 on those tires?

The trucks will be driven without cargo to the ports of Newark or Baltimore after manufacture in Allentown, Pennsylvania.

I would greatly appreciate a reply regarding this matter, as soon as possible.

Very truly yours,

Y. Toyoda -- Manager, Engineering Dept.

CC: M. Otsubo - T. Sato; 734-Tokyo; S. Nakajima-File

ID: nht95-2.44

Open

TYPE: INTERPRETATION-NHTSA

DATE: April 24, 1995

FROM: Philip R. Recht -- Acting Chief Counsel, NHTSA

TO: Jeffrey Echt -- President, Saline Electronics, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 3/10/95 LETTER FROM JEFFREY ECHT TO NHTSA CHIEF COUNSEL (OCC 10789)

TEXT: Dear Mr. Echt:

We have received your letter of March 10, 1995, asking whether it is permissible under Standard No. 108 to use the hazard warning lamps as a deceleration warning system.

Paragraph S5.5.10(a) states that "Turn signal lamps, hazard warning signal lamps, and school bus warning lamps shall be wired to flash." With this in mind, "and the fact that hazard warning indicators are commonly used to warn high-speed trailing traffic that a leading vehicle or vehicles are moving slowly or stopped", you have asked:

"1. Would a device which automatically activated a vehicle's hazard warning system at the onset of high, braking induced deceleration and deactivated the hazard warning system upon release of the brake pedal (following automatic activation) be permissib le under FMVSS 108? This assumes that the device will not prevent activation or cause deactivation of the hazard warning system if the mandatory vehicular hazard warning signal operating unit has been activated by the driver."

Heretofore, the agency's opinion letters on deceleration warning systems have covered those that operate through lamps that are steady burning in use (to Norman H. Dankert on June 3, 1990, and to Bob Abernethy on September 7, 1990), or through original e quipment lamps that are additional to those required by the standard (letter of July 30, 1993, to the Commonwealth of Virginia). In those instances, we have advised that a deceleration warning system must be steady burning in use.

Your question raises the issue of whether a flashing deceleration warning system is acceptable if it operates through original equipment lamps that are intended to flash when they are used. Flexible asked a similar question with respect to a supplementa ry lighting system. We advised it (letter of December 8, 1986) that simultaneous use of flashing and steady-burning lamps have the potential for creating confusion in vehicles to the rear and impairing the effectivess of the required stop lamps within t he meaning of S5.1.3 (the provision of Standard No. 108 that governs the permissibility of supplemental original lighting equipment). We believe that the same conclusion also applies to wiring the hazard warning system to operate as a high deceleration warning system as well. Thus, we do not view this system as permissible under Standard No. 108. Obviously, complying vehicles are manufactured so that it is possible for a driver to simultaneously activate the hazard warning system and stop lamp system. However, we believe that this happens infrequently, and when it does, it is a conscious choice of the operator and not of a system.

Because of the conclusion we have reached above, your second question is moot.

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.

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