ID: nht94-2.20

TYPE: Interpretation-NHTSA

DATE: April 7, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Ulrich Metz -- Automotive Division, Robert Bosch GmbH (Germany)

TITLE: None

ATTACHMT: Attached to letter dated 6/9/93 from Ulrich Metz to NHTSA (OCC 9194)

TEXT:

This responds to your letter to this agency regarding a new windshield wiper system you intend to develop for front windshield. I apologize for the delay in responding.

The drawing you enclosed with your letter shows a wiper system consisting of one wiper arm and blade, as distinguished from the conventional systems consisting of two wiper arms and blades. Your wiper system takes different paths on the forward and the return strokes of the wiper cycle. Thus, as you stated in your letter, "the vision areas are fulfilled only in the sum of forward and return movement." You asked whether that is permissible under Federal Motor Vehicle Safety Standard (FMVSS) No. 104, W indshield Wiping and Washing systems (copy enclosed), and if so, whether the minimum frequencies specified by FMVSS 104 apply to this wiper system. As explained below, the answer to both questions is yes.

The essential feature of a windshield wiper system, from a safety standpoint, is its ability to clear a specific portion of the windshield. The number of wipers necessary to provide the driver with a sufficient field of view is not specified in FMVSS 10 4. Therefore, the number of wipers is immaterial so long as the minimum percentages of critical areas are cleared.

The areas to be wiped are specified in paragraphs S4.1.2 and S4.1.2.1 of the standard. S4.1.2 establishes three windshield areas for passenger car windshields, designated as areas "A," "B," and "C." Each area is required to have a certain percentage of the glazing area wiped as shown in Figures 1 and 2 of SAE Recommended Practice J903a, May 1966 (copy enclosed), using the angles specified in Tables I, II, III, and IV of FMVSS 104, as applicable. Those tables apply to passenger cars of varying overall widths, namely, from less than 60 inches to more than 68 inches. The angles set forth in the tables vary according to the overall width of the vehicle. Finally, paragraph S4.1.2 provides that the percentage of each area required to be cleared must als o be within the area bounded by a perimeter line on the glazing surface one inch from the edge of the daylight opening.

With that background in mind, I will address your first question. FMVSS 104 does not specify whether the wiper needs to clear a windshield on either or both strokes. SAE Recommended Practice J903a, at paragraph 2.5, however, defines an effective wipe p attern as "that portion of the windshield glazing surface which is cleaned when the wiper blade travels THROUGH A CYCLE) (emphasis added). A "cycle" is defined in paragraph 2.14 of SAE Recommended Practice J903a as consisting of "wiper blade movement du ring system operation from one extreme of the windshield wipe pattern to the other extreme AND RETURN" (emphasis added). It is NHTSA's opinion, therefore, that so long as the required windshield area is cleared by your wiper in a complete cycle, the

requirements of paragraphs S4.1.2 and S4.1.2.1, FMVSS 104, have been met.

As indicated above, your wiper system must comply with the minimum frequencies specified in section S4.1.1, Frequency, of FMVSS 104. That section requires that each windshield wiping system must have at least two frequencies or speeds. One must be at l east 45 cycles per minute (cpm), regardless of engine load and speed. The other must be at least 20 cpm, also regardless of engine load and speed. In addition, the difference between the higher and lower speeds must be at least 15 cpm, regardless of en gine load and speed. There are no exceptions to these frequency requirements, regardless of the number or design of the wiper arms comprising the system.

Your letter did not indicate whether your wiper system is designed to be used on passenger cars or motor vehicles other than passenger cars, or both. Please note that section S2 of FMVSS 104, Application, provides that the standard applies to multipurpo se passenger vehicles, trucks, and buses in addition to passenger cars. All those vehicles are required to have power-driven windshield wiping systems that meet the frequency requirements of section S4.1.1. The wiped area requirements of S4.1.2, howeve r, apply only to passenger cars.

I hope this information will be helpful to you. Should you have any further questions or need any additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992.

ID: nht95-5.42

TYPE: INTERPRETATION-NHTSA

DATE: July 31, 1995

FROM: Steven B. Fisher -- Kostow And Daar, P.C.

TO: Phillip R. Recht -- Chief Counsel, NHTSA

TITLE: Re: Motor Vehicle Safety Standard No. 108

ATTACHMT: ATTACHED TO 8/30/95 LETTER FROM JOHN WOMACK TO STEVEN B. FISHER (REDBOOK 2; STD. 108)

TEXT: Dear Mr. Recht:

I am writing you in hopes of obtaining an opinion and/or interpretation concerning Safety Standard No. 108, including but not limited to Table II of such Motor Vehicle Safety Standard.

Pursuant to the above safety standard, with respect to truck, trailer identification lights (red), what is meant exactly by the word "practicable" as used in @@ 5.3.1.1, and 5.3.1.4.

Secondly, whose responsibility is it to assess, or in other words to determine, what is "practicable" and what is not "practicable" relative to the placement and location of rear, identification lamps (red). Is it the manufacturer of the particular identification light who provides the trailer manufacturer with tye type of identification light requested or is it the duty of the trailer manufacturer who receives the identification light for incorporation into its trailer to make such determination as they see fit in accordance with No. 108 and in light of the particular design/configuration of the trailer involved?

Third, given the "practicability" term as used in the above standard, combined with the many number of different types of trailers which are made each year and travel the public roadways, is there any way for a manufacturer of a single, rear identification light to know for certain, anticipate or otherwise predict where the trailer manufacturer will ultimately place and/or locate the identification lights on any given trailer?

Your cooperation and assistance concerning the above request for an advisory opinion and/or interpretation of the aforementioned standard would be greatly appreciated.

Should you have any questions, please feel free to give me a call. My direct number is 312/474-1404. Thanks again.

ID: nht95-3.63

TYPE: INTERPRETATION-NHTSA

DATE: July 31, 1995

FROM: Steven B. Fisher -- Kostow And Daar, P.C.

TO: Phillip R. Recht -- Chief Counsel, NHTSA

TITLE: Re: Motor Vehicle Safety Standard No. 108

ATTACHMT: ATTACHED TO 8/30/95 LETTER FROM JOHN WOMACK TO STEVEN B. FISHER (REDBOOK 2; STD. 108)

TEXT: Dear Mr. Recht:

I am writing you in hopes of obtaining an opinion and/or interpretation concerning Safety Standard No. 108, including but not limited to Table II of such Motor Vehicle Safety Standard.

Pursuant to the above safety standard, with respect to truck, trailer identification lights (red), what is meant exactly by the word "practicable" as used in @@ 5.3.1.1, and 5.3.1.4.

Secondly, whose responsibility is it to assess, or in other words to determine, what is "practicable" and what is not "practicable" relative to the placement and location of rear, identification lamps (red). Is it the manufacturer of the particular i dentification light who provides the trailer manufacturer with tye type of identification light requested or is it the duty of the trailer manufacturer who receives the identification light for incorporation into its trailer to make such determination as they see fit in accordance with No. 108 and in light of the particular design/configuration of the trailer involved?

Third, given the "practicability" term as used in the above standard, combined with the many number of different types of trailers which are made each year and travel the public roadways, is there any way for a manufacturer of a single, rear identific ation light to know for certain, anticipate or otherwise predict where the trailer manufacturer will ultimately place and/or locate the identification lights on any given trailer?

Your cooperation and assistance concerning the above request for an advisory opinion and/or interpretation of the aforementioned standard would be greatly appreciated.

Should you have any questions, please feel free to give me a call. My direct number is 312/474-1404. Thanks again.

ID: nht94-6.47

DATE: April 7, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Ulrich Metz -- Automotive Division, Robert Bosch GmbH (Germany)

TITLE: None

ATTACHMT: Attached to letter dated 6/9/93 from Ulrich Metz to NHTSA (OCC 9194)

TEXT:

This responds to your letter to this agency regarding a new windshield wiper system you intend to develop for front windshield. I apologize for the delay in responding.

The drawing you enclosed with your letter shows a wiper system consisting of one wiper arm and blade, as distinguished from the conventional systems consisting of two wiper arms and blades. Your wiper system takes different paths on the forward and the return strokes of the wiper cycle. Thus, as you stated in your letter, "the vision areas are fulfilled only in the sum of forward and return movement." You asked whether that is permissible under Federal Motor Vehicle Safety Standard (FMVSS) No. 104, Windshield Wiping and Washing systems (copy enclosed), and if so, whether the minimum frequencies specified by FMVSS 104 apply to this wiper system. As explained below, the answer to both questions is yes.

The essential feature of a windshield wiper system, from a safety standpoint, is its ability to clear a specific portion of the windshield. The number of wipers necessary to provide the driver with a sufficient field of view is not specified in FMVSS 104. Therefore, the number of wipers is immaterial so long as the minimum percentages of critical areas are cleared.

The areas to be wiped are specified in paragraphs S4.1.2 and S4.1.2.1 of the standard. S4.1.2 establishes three windshield areas for passenger car windshields, designated as areas "A," "B," and "C." Each area is required to have a certain percentage of the glazing area wiped as shown in Figures 1 and 2 of SAE Recommended Practice J903a, May 1966 (copy enclosed), using the angles specified in Tables I, II, III, and IV of FMVSS 104, as applicable. Those tables apply to passenger cars of varying overall widths, namely, from less than 60 inches to more than 68 inches. The angles set forth in the tables vary according to the overall width of the vehicle. Finally, paragraph S4.1.2 provides that the percentage of each area required to be cleared must also be within the area bounded by a perimeter line on the glazing surface one inch from the edge of the daylight opening.

With that background in mind, I will address your first question. FMVSS 104 does not specify whether the wiper needs to clear a windshield on either or both strokes. SAE Recommended Practice J903a, at paragraph 2.5, however, defines an effective wipe pattern as "that portion of the windshield glazing surface which is cleaned when the wiper blade travels THROUGH A CYCLE) (emphasis added). A "cycle" is defined in paragraph 2.14 of SAE Recommended Practice J903a as consisting of "wiper blade movement during system operation from one extreme of the windshield wipe pattern to the other extreme AND RETURN" (emphasis added). It is NHTSA's opinion, therefore, that so long as the required windshield area is cleared by your wiper in a complete cycle, the

requirements of paragraphs S4.1.2 and S4.1.2.1, FMVSS 104, have been met.

As indicated above, your wiper system must comply with the minimum frequencies specified in section S4.1.1, Frequency, of FMVSS 104. That section requires that each windshield wiping system must have at least two frequencies or speeds. One must be at least 45 cycles per minute (cpm), regardless of engine load and speed. The other must be at least 20 cpm, also regardless of engine load and speed. In addition, the difference between the higher and lower speeds must be at least 15 cpm, regardless of engine load and speed. There are no exceptions to these frequency requirements, regardless of the number or design of the wiper arms comprising the system.

Your letter did not indicate whether your wiper system is designed to be used on passenger cars or motor vehicles other than passenger cars, or both. Please note that section S2 of FMVSS 104, Application, provides that the standard applies to multipurpose passenger vehicles, trucks, and buses in addition to passenger cars. All those vehicles are required to have power-driven windshield wiping systems that meet the frequency requirements of section S4.1.1. The wiped area requirements of S4.1.2, however, apply only to passenger cars.

I hope this information will be helpful to you. Should you have any further questions or need any additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992.

ID: 9194

Mr. Ulrich Metz
Automotive Division
Robert Bosch GmbH
K4/ERW3
Postfach 1163
77813 Buel
Germany

Dear Mr. Metz:

This responds to your letter to this agency regarding a new windshield wiper system you intend to develop for front windshields. I apologize for the delay in responding.

The drawing you enclosed with your letter shows a wiper system consisting of one wiper arm and blade, as distinguished from the conventional systems consisting of two wiper arms and blades. Your wiper system takes different paths on the forward and the return strokes of the wiper cycle. Thus, as you stated in your letter, "the vision areas are fulfilled only in the sum of forward and return movement." You asked whether that is permissible under Federal Motor Vehicle Safety Standard (FMVSS) No. 104, Windshield Wiping and Washing Systems (copy enclosed), and if so, whether the minimum frequencies specified by FMVSS 104 apply to this wiper system. As explained below, the answer to both questions is yes.

The essential feature of a windshield wiper system, from a safety standpoint, is its ability to clear a specific portion of the windshield. The number of wipers necessary to provide the driver with a sufficient field of view is not specified in FMVSS 104. Therefore, the number of wipers is immaterial so long as the minimum percentages of critical areas are cleared.

The areas to be wiped are specified in paragraphs S4.1.2 and S4.1.2.1 of the standard. S4.1.2 establishes three windshield areas for passenger car windshields, designated as areas "A", "B", and "C." Each area is required to have a certain percentage of the glazing area wiped as shown in Figures 1 and 2 of SAE Recommended Practice J903a, May 1966 (copy enclosed), using the angles specified in Tables I, II, III, and IV of FMVSS 104, as applicable. Those tables apply to passenger cars of varying overall widths, namely, from less than 60 inches to more than 68 inches. The angles set forth in the tables vary according to the overall width of the vehicle. Finally, paragraph S4.1.2 provides that the percentage of each area required to be cleared must also be within the area bounded by a perimeter line on the glazing surface one inch from the edge of the daylight opening.

With that background in mind, I will address your first question. FMVSS 104 does not specify whether the wiper needs to clear a windshield on either or both strokes. SAE Recommended Practice J903a, at paragraph 2.5, however, defines an effective wipe pattern as "that portion of the windshield glazing surface which is cleaned when the wiper blade travels through a cycle) (emphasis added). A "cycle" is defined in paragraph 2.14 of SAE Recommended Practice J903a as consisting of "wiper blade movement during system operation from one extreme of the windshield wipe pattern to the other extreme and return" (emphasis added). It is NHTSA's opinion, therefore, that so long as the required windshield area is cleared by your wiper in a complete cycle, the requirements of paragraphs S4.1.2 and S4.1.2.1, FMVSS 104, have been met.

As indicated above, your wiper system must comply with the minimum frequencies specified in section S4.1.1, Frequency, of FMVSS 104. That section requires that each windshield wiping system must have at least two frequencies or speeds. One must be at least 45 cycles per minute (cpm), regardless of engine load and speed. The other must be at least 20 cpm, also regardless of engine load and speed. In addition, the difference between the higher and lower speeds must be at least 15 cpm, regardless of engine load and speed. There are no exceptions to these frequency requirements, regardless of the number or design of the wiper arms comprising the system.

Your letter did not indicate whether your wiper system is designed to be used on passenger cars or motor vehicles other than passenger cars, or both. Please note that section S2 of FMVSS 104, Application, provides that the standard applies to multipurpose passenger vehicles, trucks, and buses in addition to passenger cars. All those vehicles are required to have power-driven windshield wiping systems that meet the frequency requirements of section S4.1.1. The wiped area requirements of S4.1.2, however, apply only to passenger cars.

I hope this information will be helpful to you. Should you have any further questions or need any additional information, please feel free to contact Walter Myers of my staff at this address or at (202) 366-2992.

Sincerely,

John Womack Acting Chief Counsel

Enclosures ref:104 d:4/7/94

ID: 1653y

The Honorable Jim Bates
Member, U.S. House of Representatives
430 Davidson St., Suite A
Chula Vista, CA 92010

Dear Mr. Bates:

This is in reply to your letter of October 19, l988, with reference to an invention by your constituent, Angelo R. Collica. You have asked for "the requirements necessary to install lighting devices on motor vehicles."

Since we do not have a description of Mr. Collica's device, our answer must therefore be general in nature. There are different answers, depending upon whether a device is installed before or after the first sale of a vehicle.

A supplementary lighting device installed on a vehicle by a vehicle manufacturer or dealer before its first sale to a consumer is permissible as long as it does not impair the effectiveness of lamps, reflective devices, and associated equipment that are required by the Federal motor vehicle safety standard on lighting. Examples of impairment are diminished brightness of a lamp due to interference with its wiring, or a confusion of its function through close proximity or signal of the supplementary device. In general, also, all lighting equipment other than hazard warning/turn signals, and headlamps flashed for signalling purposes, must be steady-burning in use. Whether a device creates an impairment is a determination to be made by the vehicle manufacturer in its certification of compliance with the Federal safety standards, or by the dealer, before sale of the vehicle.

The installation of a supplementary lighting device on a vehicle after the vehicle's first sale to a consumer is acceptable under Federal law, provided that the installation does not degrade the performance of any device or element of design installed in accordance with any Federal motor vehicle safety standard. This prohibition applies to vehicle manufacturers, distributors, dealers and repair businesses. It does not, however, apply if the supplementary lighting device is installed by the vehicle owner.

The legality of operating a supplementary device, installed after vehicle sale, is primarily determinable under the laws of any State in which a vehicle using it is registered or driven. The American Association of Motor Vehicle Administrators, 4600 Wilson Blvd., Arlington, Va. 22203, is able to advise on State laws.

I hope that this has been helpful to you.

Sincerely,

Diane K. Steed

/ref:108 d:l/23/89

ID: 77-3.3

TYPE: INTERPRETATION-NHTSA

DATE: 06/16/77

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Lucas Industries North America, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of May 13, 1977, to the Administrator asking whether the circuitry diagram that you enclosed would allow compliance with S4.5.2 of Federal Motor Vehicle Safety Standard No. 108.

Paragraph S4.5.2 requires that "each vehicle shall have a means for indicating to the driver when the upper beams of the headlamps are on that conforms to SAE Recommended Practice J564a, April 1964 . . . ." Your diagram appears to meet the specifications of J564a allowing compliance of the system with S4.5.2 when installed in a motor vehicle. The entity legally responsible for compliance with S4.5.2, of course, is the vehicle manufacturer who must certify that its products meet all applicable Federal motor vehicle safety standards.

YOURS TRULY,

Lucas Industries North America Inc

MAY 13, 1977

The Administrator National Highway Traffic Safety Administration

Our sister company in Birmingham England, Lucas Electrical Limited, requests clarification of Section 4.5.2 of Standard 108 - Lamps, Reflective Devices and Associated Equipment - and SAE Recommended Practice J564, which is referenced in Standard 108, Section 4.5.2.

We submit a diagram of a four headlamp installation in which a Lucas Model 21SA switch and a normally closed relay is used to ensure that the headlight circuits cannot be held in the open condition. Manual and auto reset switches are also included in the circuit to ensure correct circuit operation. We are also submitting traces showing the transient voltage conditions when switching from:

a) Main beam to dip beam

b) Dip beam to main beam

This circuitry we have developed allows, as far as we are aware, for us to comply with Section 4.5.2 of Standard 108. We look forward to receiving whatever comments you deem applicable and will be pleased to supply additional material if you so desire.

Eric E Gough Staff Assistant (Technical) 21SA HEADLAMP BEAM SWITCH CIRCUIT

(Graphics omitted) (Illegible Text)

(Graphic omitted)

ID: nht94-1.79

TYPE: Interpretation-NHTSA

DATE: March 16, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Jerry L. Steffy -- Triumph Designs, Ltd. (England)

TITLE: None

ATTACHMT: Attached to faxes dated 2/11/94 and 2/10/94 from Jerry L. Steffy to Taylor Vinson (OCC 9661)

TEXT:

This responds to your FAXes of February 10 and 11, 1994, to Taylor Vinson of this Office.

You have informed us that in Canada you were able recently "to use ECE Reg. 20 in lieu of FMVSS 108 for a particular headlamp use." You have asked whether it is possible to do the same in the United States.

The answer depends upon whether the ECE Reg. 20 headlamp also meets FMVSS No. 108. Motor vehicles manufactured for sale in the United States must be equipped with headlamps that comply with FMVSS No. 108. This standard does not incorporate ECE Reg. 20. Therefore, importation and sale in the United States of any motor vehicle equipped with an ECE Reg. 20 headlamp that does not meet Standard No. 108 would be in violation of our law.

You have also asked whether our temporary exemption procedures, 49 CFR Part 555, would permit you to apply for an exemption for this headlamp on the grounds of "an equivalent overall level of motor vehicle safety." After one model year, you would change to a headlamp that meets FMVSS 108.

The exemption procedures are available to manufacturers of motor vehicles, but not motor vehicle equipment. Thus, the manufacturer of an ECE Reg. 20 headlamp could not apply for an exemption. The appropriate petitioner would be the manufacturer of a mo tor vehicle on which a Reg. 20 headlamp is installed as original equipment. We assume that Triumph Designs is associated with the manufacturer of Triumph motorcycles, and this manufacturer would be eligible to submit a petition under Part 555.

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

ID: nht81-3.43

DATE: 11/24/81

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Dart Transit Company

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your recent telephone conversations with Roger Fairchild of this office, in which you requested our approval for Freuhauf to change the vehicle identification numbers (VIN's) on certain of its trailers which your company purchased. As we understand your situation, your company intended to purchase and Freuhauf intended to provide you 1980 model year trailers. The trailers you actually received had Freuhauf's statements of origin indicating they are 1980 model year trailers. However, the first character of the third section of the trailers' VIN's is apparently a "B," thus indicating that the model year is 1981. Freuhauf reportedly wishes to correct the VIN's and use an "A" instead of a "B," thus indicating the 1980 model year. We understand too that these vehicles were not manufactured in serial sequence, but are scattered randomly through the manufacturer's production run.

Based on our understanding of the facts you have provided us, this agency does not have any objection to this change being made by Freuhauf. The requirements of Federal Motor Vehicle Safety Standard No. 115 provide the manufacturers with substantial latitude regarding model year designation. S4.5.3.1 of the Standard requires that the first character of the third section of the VIN indicate the model year. S3 of the Standard defines "model year" as "the year used to designate a discrete vehicle model irrespective of the calendar year in which the vehicle was actually produced, so long as the actual period is less than 2 years." In issuing the standard, the agency anticipated that once the manufacturer of a discrete vehicle model switched from designating those vehicles with a given model year (e.g., 1983) to the next model year (i.e., 1984), the manufacturer would uniformly designate all vehicles with that new model year until it switched to designating all vehicles uniformly as being produced in the following model year (i.e., 1985). More than any other user of the VIN, the manufacturer itself would benefit from this practice since it promotes the orderliness of records. However, Standard No. 115 does not actually require that this practice be followed. Further, the departure from the practice in a limited circumstance should not pose any significant practical problem for the users of the VIN's of trailers in question.

ID: nht79-1.15

DATE: 10/01/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Leo Bachynsky -- Laboratory Manager, R.E. Dietz Co.

TITLE: Emergency Warning Lamp - Use of Relfex

ATTACHMT: 8/21/79 letter from Leo Bachynsky to NHTSA

TEXT:

Dear Mr. Bachynsky:

This is in reply to your letter of August 21, 1979, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108 as it may apply to a proposed new product of your company.

This product, as you have described it, is a bi-directional Emergency Vehicle Warning Lamp, with one lens facing to the front of the vehicle, and one to the rear. Each lens contains a 5/8 inch wide band of reflex reflector around its periphery. The lamp would be supplied in a variety of colors (red, blue, yellow) and a similar device, less the reflex reflector area, is currently in production.

You have asked whether the inclusion of the reflex reflector in the device, "impairs the effectiveness of the required equipment" within the prohibition of S4.1.3. You have also asked whether the equipment and location tables of Standard No. 108 restrict the use of a red reflex reflector facing the front and yellow reflex reflector facing the rear.

The determination of whether installation of additional lighting devices impairs the effectiveness of required equipment may be made either by the vehicle manufacturer or by NHTSA. Since your company already markets an emergency vehicle warning lamp we shall assume for purposes of discussion that vehicle manufacturers have determined that the lamp as currently manufactured does not impair other lighting equipment. Nor does it appear to us that the addition of the limited reflex reflector area would contribute to a degradation of the effectiveness of required lighting equipment, although a definitive judgment could not be made until the lamps were actually installed on a vehicle. The tables do not apply to supplementary lighting equipment such as your emergency lamp though the agency believes there is less likelihood of confusion if the public associates amber lighting devices with the front part of a vehicle, and red ones with the rear.

Sincerely,

Frank Berndt Chief Counsel

August 21, 1979

Chief Council NHTSA 400 Seventh Street S.W. Washington, D.C. 20590

Dear Sir:

Our company is presently developing a new product and is in need of a clarification concerning the legality of the proposed product as it pertains to FMVSS 108.

Briefly, the device is a bi-directional Emergency Vehicle Warning Lamp consisting of two 7-1/2 inch diameter lenses. The lenses contain a 5/8 inch wide band of reflex reflector around their periphery. The two lenses are locked to a mounting flange by a special locking feature and two screws. When mounted, the device will have one lens facing to the front of the vehicle and the other to the rear. The device is to be supplied in a variety of colors, red, yellow, blue, and can be used in either a steady or flashing state.

We manufacture a similar device less the reflex reflector area and previous sales data indicates the majority of the market for this type of device is for tow trucks and utility company vehicles.

We are aware of the fact that Emergency Warning Lamps are not regulated by FMVSS 108 or any other Federal standard, but rather our questions concern the reflex reflector area in the device.

The areas that need clarification with respect to our application are the following:

1. Paragraph S.4.1.3 of FMVSS 108 - "No additional lamp, reflective device or other motor vehicle equipment shall be installed that impairs the effectiveness of the equipment required by this standard."

Does this Paragraph S.4.1.3. restrict the use of the reflex reflector in our proposed device as imparing effectiveness of required equipment?

2. Do Tables 1-4 of FMVSS 108 "Required Equipment for Motor Vehicles" and "Locations of Required Equipment" restrict the use of a red reflex reflector facing the front and yellow reflex reflector facing the rear of the vehicle?

An early reply will be appreciated.

Enclosed is our blueprint of the subject device and an advertising poster showing exact application of the intended device.

Sincerely,

Leo Bachynsky Laboratory Manager

LB/sg Enclosure (2)