ID: 1985-04.29

TYPE: INTERPRETATION-NHTSA

DATE: 11/18/85

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Mr. David Gruenzner

TITLE: FMVSS INTERPRETATION

TEXT:

November 18, 1985 Mr. David Gruenzner President, Future Tech Inc. P.O. Box 26B Mankato, MN 56002 Dear Mr. Gruenzner: This is in reply to your letter of September 23, 1985, asking for an interpretation of Federal Motor Vehicle Safety Standard No. 108 as it applies to an aftermarket high-mounted stop lamp/turn signal lamp system. You intend to market three models, as more completely described in the next paragraph. All models are mounted in the interior of the car. Our primary concern is the possibility that the interior-mounted unit will cause undesirable reflections in the rear window, reducing the ability of the operator to judge conditions to the rear of his vehicle as seen through the rear view mirror. For this reason, Standard No. 108 requires the new center-mounted stop lamps mounted on the interior to be provided with means to minimize such reflections. These lamps now in production incorporate shrouds that abut the rear window glazing. Though your after market device would not be prohibited by Standard No. 108 since it does not appear to impair the effectiveness of lighting equipment required by the standard, we encourage you to incorporate design features which will prevent undesirable reflections. Also care should be taken to ensure that, when the device is installed, it does not impair the field of view required for rear view mirrors by Safety Standard No. 111. Your device consists of eight miniature lamps, four mounted on each side of the vertical centerline. We also have some additional concerns about the operation of one of your three models. In the first model, in the turn signal mode, the lamps operate sequentially from the center outward in the direction of the intended turn. In the stop lamp mode, the entire unit will illuminate, "sending a sequential (sic) flashing beam from the middle to both sides." We view the sequential flashing of the lights from the center outwards in the stop lamp mode as prohibited by paragraph S4.6 of the standard which requires all lamps that are flashed for signaling purposes. However, the stop function in the second model is indicated by a steady-burning in use, except for turn signal/hazard warning signal lamps, and headlamps and side marker lamps that are flashed for signaling purposes. However, the stop function in the second model is indicated by a steady-burning light, thus complying with our requirements. In the third model, there will be an additional amber colored lens mounted on top of the red lens. The brake signal will be indicated by a steady red light, while the turn signals will be indicated by flashing amber ones. This method of operation is also acceptable under Standard No. 108 which permits rear turn signals to be either amber or red.

We are unable to assist you with State laws that may affect your devices. We suggest you contact the vehicle administrators in the States where you intend to market your system. I hope that this is responsive to your request. Sincerely, Original Signed By Erika Z. Jones Chief Counsel

ID: nht76-3.39

DATE: 06/21/76

FROM: THOMAS L. HERLIHY FOR STEPHEN P. WOOD -- NHTSA

TO: Mr. Jack Roadman

TITLE: FMVSR INTERPRETATION

TEXT: This is in response to your letters of February 26 and March 8, 1976, concerning the certification of a truck that you wish to build with a chassis that you have purchased from International Harvester. You have indicated that the chassis did not include an engine, transmission, or radiator. You installed a diesel engine, transmission, and a new driveshaft, and made various modifications to the chassis. You have had difficulties in persuading a body manufacturer to install a truck body.

The source of your difficulties appears to be a misunderstanding of the requirements of the National Traffic and Motor Vehicle Safety Act of 1966 (the Act) and the accompanying certification regulations. Pursuant to the Act, the National Highway Traffic Safety Administration has issued Federal motor vehicle safety standards. These standards apply to completed motor vehicles and to certain items of motor vehicle equipment (e.g., brake hoses, tires). The manufacturer of a motor vehicle or an item of equipment to which a standard applies is required by Section 114 of the Act to certify that his product complies with all applicable Federal motor vehicle safety standards.

"Incomplete vehicle" is defined in 49 CFR Part 568, Vehicles Manufactured in Two or More Stages, as:

an assemblage consisting, as a minimum, of frame and chassis structure, power train, steering system, suspension system, and braking system, to the extent that those systems are to be part of the completed vehicle, that requires further manufacturing operations, other than the addition of readily attachable components, such as mirrors or tire and rim assemblies, or minor finishing operations such as painting, to become a completed vehicle.

An incomplete vehicle is, strictly speaking, an item of motor vehicle equipment. There are no Federal motor vehicle safety standards that apply directly to these particular equipment items, and thus there is presently no certification requirement for incomplete vehicles. The manufacturer of an incomplete vehicle is required by Part 568, however, to furnish an "incomplete vehicle document". This document, which is described in @ 568.4, must indicate the conformity status of the incomplete vehicle with respect to each standard that applies to the vehicles into which it may be completed.

The chassis that you bought from International Harvester (IH) was an item of motor vehicle equipment to which no standards apply. Therefore, IH was not required to furnish you with a certification of compliance. Further, the chassis was not an incomplete vehicle because it lacked an engine and transmission. Therefore, IH was not required to furnish an incomplete vehicle document. Because of your operations on the chassis, you are the manufacturer of an incomplete vehicle. You, therefore, are the person required to furnish an incomplete vehicle document.

Your letter also indicated a concern they you were not given a "certificate of origin" by International Harvester when you purchased the chassis. Federal law does not require the issuance of a certificate of origin. Unless you intended to refer to the Section 114 "certification" discussed above, I assume that you have in mind a document that would be the subject of Pennsylvania state law.

Copies of the Act and the certification regulations are enclosed for your convenience.

ID: nht94-1.41

TYPE: Interpretation-NHTSA

DATE: February 7, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Cheryl Graham -- District Manager, Northeast Region, ARI

TITLE: None

ATTACHMT: Attached to letter dated 11/10/93 from Cheryl Graham to Chief Counsel's Office, NHTSA (OCC-9345)

TEXT:

We have received your letter of November 10, 1993, asking about the permissibility of aftermarket installation of an auxiliary pair of stop lamps "at each side of the rear window."

by way of background information the National Highway Traffic Safety Administration (NHTSA) issues Federal motor vehicle safety standards under the authority of the National Traffic and Motor Vehicle Safety Act (Safety Act). Under that Act, the sole res traint upon modifications to vehicles in use is that, if performed by a manufacturer, distributor, dealer, or motor vehicle repair business, the modifications must not "knowingly render inoperative, in whole or in part, any device or element of design in stalled on...a motor vehicle in compliance with an applicable Federal motor vehicle safety standard...." (15 U.S.C. 1397(a)(2)(A)).

In NHTSA's view, if the modifications tend to impair the safety effectiveness of the "device or element of design," then, at the minimum, a partial inoperability may have occurred within the meaning of the statutory prohibition. The question raised by y our letter, therefore, is whether the installation of the auxiliary stop lamps in that location would impair the effectiveness of the three original equipment stop lamps.

NHTSA decided to require the center highmounted stop lamp in addition to the then-existing original equipment two-lamp stop lamp system following research which indicated that a three-lamp system of this configuration was demonstrably more effective in p reventing rear end crashes than other rear end lighting systems that were tested, and considerably lower in cost. Included in the testing was a four-lamp system which incorporated two lamps at each side of the rear window, but no tests were conducted on the five-lamp system you describe.

The reasons for the better performance of the three-lamp system are unclear, but the triangular lighting array proved to be more effective than the trapezoidal four-lamp system (and more effective than a system tested which separated the usual stop lamp from the tail lamp).

Your customer appears to believe that the ability of following drivers to avoid rear end crashes is enhanced by a five-lamp stop lamp system. On the other hand, your proposed system, by incorporating the two lamps at each side of the rear window, would appear to change the lighting array.

We cannot say that the five-lamp system would either enhance or detract from safety. Thus, we cannot find that the additional lamps would "render inoperative" the original equipment three-lamp system, and it would be permissible under the regulations of this agency. However, the

permissibility of such a modification would be determinable under State law. We are unable to advise you on the laws of the various States and suggest that you write the American Association of Motor Vehicle Administrators for an interpretation. Its add ress is 4600 Wilson Boulevard, Arlington, VA 22203.

You have also asked "if the work is done improperly and results in an accident, where does the liability lie?" This question is a matter of state law, and we suggest that you consult a local attorney concerning it.

ID: nht94-2.1

TYPE: Interpretation-NHTSA

DATE: March 28, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Thomas D. Turner -- Manager, Engineering Services, Blue Bird Body Company

TITLE: None

ATTACHMT: Attached to letter dated 2/21/94 from Thomas D. Turner to John Womack (OCC 9719)

TEXT:

This responds to your letter of February 21, 1994, requesting further clarification of the requirements of S5.5.3(c) of Standard No. 217, Bus Emergency Exits and Window Retention and Release (as amended at 57 FR 49413; November 2, 1992). Section S5.5.3( c) states that "(e)ach opening for a required emergency exit shall be outlined around its outside perimeter with a minimum 3 centimeters wide retroreflective tape." *1 Your letter referenced our July 7, 1993 letter to you in which we stated that S5.5.3 (c) permits interruptions in the tape necessary to accommodate curved surfaces and functional components. You requested confirmation "that retro-reflective tape around the perimeter of the rear of a school bus can be used to satisfy the requirements of S5.5.3(c)."

I cannot interpret the requirements of S5.5.3(c) as you request, since for many, if not most, designs the nearest possible location will be closer than the perimeter of the bus. While we appreciate your concerns about durability if numerous cuts or notc hes are made to accommodate rivets, our July 7 letter stated that manufacturers have the option of placing the retroreflective tape immediately adjacent to the rivets, rather than over the rivets. As an example, from the illustrations you enclosed, it a ppears that it may be possible to apply retroreflective tape outside the rivets adjacent to the lower portions of the door. Thus, that would be the nearest possible location, rather than the perimeter of the bus itself. I note, however, that the illust rations do not provide sufficient detail of all obstructions for us to determine the nearest possible location for each design.

I also note that your letter stated in support of your request that all school buses are required to have a rear emergency exit. While this is true, the type of emergency exit will vary and retroreflective tape at the perimeter of the exit would allow r escuers to immediately know the precise location of the exit. Moreover, retroreflective tape at the perimeter would enable rescuers to immediately know which type of exit is in this location. This information could be vitally important. Because push-ou t windows are not required to have a means of releasing the exit from outside the bus (S5.3.3.2), this information would allow rescuers to quickly determine that they should move to the sides of the bus to locate an exit they can open.

Your letter asked the agency to treat it as a petition for rulemaking if we did not interpret the standard as you requested. You will be notified of our decision to grant or deny your petition.

I hope you find this information helpful. If you have any other questions, please contact us at this address or by phone at (202) 366-2992.

*1 The July 7, 1993 letter also stated that the agency planned to issue a correction notice of the November 2, 1992 rule that would specify a minimum size of 2.5 cm for the tape. This notice has not yet been published. Until the correction is issued, NHTSA will not take enforcement measures regarding tape size against a manufacturer who uses 1 inch wide retroreflective tape.

ID: 86-6.20

TYPE: INTERPRETATION-NHTSA

DATE: 12/24/86

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Tim O. Edwards -- Safety Specialist, Kansas Dept. of Transportation, Bureau of Personnel Services

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Tim O. Edwards Safety Specialist Kansas Department of Transportation Bureau of Personnel Services 7th Floor, State Office Building Topeka, Kansas 66612

I am writing in response to your recent inquiry concerning interior over-head luggage racks on school buses. Your first question seeks this Agency's opinion on whether interior luggage racks on school buses should be considered "projections likely to cause injury" under the National Minimum Schoolbus Standards. These standards are recommendations by the National Conference on School Transportation (NCST), and are not developed by NHTSA. Requests for interpretation of these Standards should be mailed to the Interpretation Committee, addressed to :

Mr. Norman Loper Coordinator of Pupil Transportation Alabama Department of Education 304 Dexter Avenue Montgomery, AL 36130

Requests for modification to these Standards and development of new Standards should be directed to the chairman of the Interim Committee, addressed to:

Mr. Bill G. Loshbough Asst. State Supt. for Transportation Dept. of Education Education Bldg. Santa Fe, NM 87501-2786

In response to your second question, there are no federal standards or regulations which specifically address the issue of over-head luggage racks on school buses. However, Federal Motor Vehicle Safety Standard No. 222, 49 Code of Federal Regulations (CFR) S571.222 addresses the issue of school bus passenger seating and crash protection. Specifically, S5.3.1 of that standard establishes the head protection zones. As defined in S5.3.1.1, that zone extends up to a horizontal plane 40 inches above the seating reference point. If the luggage rack were to be, located within the head protection zone, the rack would have to meet the head form impact requirement in S5.3.1.2 and the head form force distribution requirement in S5.3.1.3.

Please feel free to contact this office if you have any other questions.

Sincerely,

Erika Z. Jones Chief counsel

Didre Hom, Chief Counsel NHTSA 400 Seventh Street, S. W. Washington, D.C.

Dear Ms. Hom:

In August of this year an inspection was made of a school bus in Caney, Kansas. The Highway Patrol Officer making the inspection determined that the interior over-head luggage racks found on the bus few within the National Minimum (Interior) Standards adopted by Kansas as "a projection likely to cause injury".

This has raised the question of how to handle similar luggage racks on other buses. We would request your agencies opinion on the following questions:

1. Is an interior luggage rack "a projection likely to cause injury?

2. Are there any federal standards, regulations, etc., which would specifically address this problem?

Thank you for your assistance in this matter. Please address your response to:

Kansas Department of Transportation ATTN: Tim O. Edwards, Safety Specialist Bureau of Personnel Services 7th Floor, State Office Building Topeka, Kansas 66612

Sincerely

CONNIE HAFENSTINE, CHIEF BUREAU OF PERSONNEL SERVICES

TIM O. EDWARDS SAFETY SPECIALIST II

ID: nht95-1.63

TYPE: INTERPRETATION-NHTSA

DATE: February 13, 1995

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

TO: G. Brandt Taylor -- President, Day-Night Mirrors, Inc.

TITLE: None

ATTACHMT: ATTACHED TO 12/6/94 LETTER FROM G. BRANDT TAYLOR TO PHILIP R. RECHT (OCC 10553)

TEXT: This responds to your letter asking about the requirements applicable to multiple reflectance mirrors in Federal Motor Vehicle Safety Standard (FMVSS) No. 111, Rear View Mirrors. You stated that your mirror can change its reflectivity either by mechanica lly rotating a shaft or by actuating an electrical motor.

By way of background information, the National Highway Traffic Safety Administration (NHTSA) has the authority to issue safety standards for new motor vehicles and new items of motor vehicle equipment. NHTSA does not, however, approve or certify any veh icles or items of equipment. Instead, each manufacturer is responsible for "self-certifying" that its products meet all applicable safety standards. The agency periodically tests vehicles and items of equipment for compliance with the standards.

FMVSS No. 111 specifies requirements for the performance and location of rearview mirrors. Section S11, which specifies requirements for mirror construction, provides in relevant part that

All single reflectance mirrors shall have an average reflectance of at least 35 percent. If a mirror is capable of multiple reflectance levels, the minimum reflectance level in the day mode shall be at least 35 percent and the minimum reflectance level in the night mode shall be at least 4 percent. A multiple reflectance mirror shall either be equipped with a means for the driver to adjust the mirror to a reflectance level of at least 35 percent in the event of electrical failure, or achieve such refl ectance automatically in the event of electrical failure.

You asked several questions about the requirement for adjusting the mirror in the event of electrical failure. You first asked if a manual override knob could be removable. You then asked whether a removable manual override could be supplied by the car manufacturer along with the car keys or with the owner's manual for insertion into the mirror and use only in the event of an electrical failure. You also asked about whether "west coast" mirrors and mirrors on trailer trucks could have a removable man ual override.

The answer to each of your questions is that a removable manual override knob would not be permitted. In the preamble to the final rule amending the mirror construction requirements in FMVSS No. 111, NHTSA stated that the agency's goal is to assure that multiple reflectance mirrors are capable of providing adequate images at all times during the vehicle's operation, including electrical failure situations where the mirror is unpowered. (see 56 FR 58513, November 20, 1991)

The manual override knob you discuss would serve as the means for the driver to adjust the mirror's reflectance level. However, a removable manual override knob would not always serve this purpose, since it would not necessarily always be with the mirro r. We are concerned that a removable override device may become lost or otherwise not available when a mirror's reflectance needs to be adjusted. Accordingly, since the agency's goal of providing adequate images at all times during the vehicle's operat ion would only be achieved by requiring this device to be permanent, a removable override would not be permitted.

I hope this information is helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992.

ID: nht95-1.86

TYPE: INTERPRETATION-NHTSA

DATE: March 2, 1995

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

TO: John E. Getz -- Director, Mobile Products Engineering, Ellis & Watts

TITLE: None

ATTACHMT: ATTACHED TO 10/27/94 LETTER FROM JOHN E. GETZ TO TAYLOR VINSON (OCC 10462; P.567)

TEXT: This responds to your letter asking whether certain operations that your company performs on used trailers result in the trailers being considered "newly manufactured" for purposes of the Federal motor vehicle safety standards. You stated that you somet imes change the finishing and equipment of a used trailer for a new application. As an example, you stated that you recently took a 10-year old trailer, stripped the inside, and refinished it as a mobile marketing facility. You also stated that in some cases you may cut a hole in the side and install a door for a specific application. In a telephone conversation with Dorothy Nakama of my staff, you indicated that you have also changed trailers by adding heating or air conditioning units, or making th e trailer usable as an auditorium.

In your letter, you asked whether the trailers would be considered "newly manufactured" if the running gear, VIN and the basic trailer structure do not change, but the ownership does change. You asked this question in light of the fact that change of ow nership is relevant under 49 CFR part 571.7(f) in determining whether a trailer manufactured from new and used components is considered newly manufactured. As discussed below, it is our opinion that the operations you describe do not result in the trail ers being considered newly manufactured.

By way of background information, the National Highway Traffic Safety Administration issues safety standards for new motor vehicles and new motor vehicle equipment. The agency does not provide approvals of motor vehicles or motor vehicle equipment. Ins tead, manufacturers are required to certify that their vehicles or equipment meet all applicable standards. The following represents our opinion based on the facts provided in your letter.

Section 49 CFR part 571.7(f) reads as follows:

Combining new and used components in trailer manufacture. When new materials are used in the assembly of a trailer, the trailer will be considered newly manufactured for purposes of [the safety standards], unless, at a minimum, the running gear assembly (axle(s), wheels, braking and suspension) is not new, and was taken from an existing trailer --

(1) Whose identity is continued in the reassembled vehicle with respect to the Vehicle Identification Number; and

(2) That is owned or leased by the user of the reassembled vehicle.

This section only applies when new and used materials are used in the "assembly" of a trailer. It is our opinion that the operations that you describe, i.e., where the running gear, VIN and the basic trailer structure do not change, do not constitute tr ailer assembly. Therefore, this section, including its provision concerning transfer of ownership, does not apply. We consider your operations to be in the nature of repair or refurbishment of a used trailer, which does not result in the trailer being considered newly manufactured.

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

ID: nht94-4.67

TYPE: INTERPRETATION-NHTSA

DATE: October 27, 1994

FROM: John E. Getz -- Director, Mobile Products Engineering, Ellis & Watts

TO: Taylor Vinson, NHTSA

TITLE: None

ATTACHMT: ATTACHED TO 3/2/95 LETTER FROM PHILIP R. RECHT TO JOHN E. GETZ (REDBOOK (2)); PART 571.7

TEXT: We are in the custom trailer manufacturing business. Most often we purchase new trailers and finish them, primarily inside, for specific applications such as medical trailers or trailers for specific electronic functions (see enclosed Brochure). In suc h cases our new trailer product is subject to all of the latest DOT regulations. However, in other cases we start with a used trailer and change its finishing and equipment for a new application. For example, we recently took an old (1985) vintage trai ler, stripped the inside, and refinished it for a major computer company to use as a mobile marketing facility. In this case the running gear did not change nor did the Vehicle Identification number. However, ownership did change which raised the questi on of "Newly Manufactured" as addressed in @ 571.7 "Applicability" (copy enclosed). Telephone discussions with Patrick Boyd and Ken Hardy in Vehicle Safety indicate preliminarily that this is not a newly manufactured trailer because the basic trailer st ructure did not change. However in some cases we may cut a hole in the side and install a door for a specific application.

What we are requesting is an interpretation as to whether we would fall in the category of a newly manufactured trailer if the running gear. VIN, and the basic trailer structure do not change, but the ownership does. In the example above we did add conspicuity treatment, not because it was thought to be legally required (although we did want to protect the company prior your interpretation), but mainly from a liability and safety standpoint in the event of an accident and subsequent litigation. If you have any questions regarding this request please call me at (513) 752-9000 ext. 208. Thanking you in advance. I am

Truck Trailer Manufacturers Association

RICHARD P. BOWLING

PRESIDENT

FAX TRANSMITTAL COVER SHEET

Date: October 18, 1994

Number of pages including this sheet: 1

From: Don Vierimaa

To: John Getz, 1-513-943-3395 TITLE 49 - TRAILERS

@ 671.7 Applicability.

(a) General. Except as provided in paragraphs (c) and (d) of this section, each standard set forth in Subpart B of this part applies according to its terms to all motor vehicles or items of motor vehicle equipment the manufacture of which is completed on or after the effective date of the standard.

(f) Combining new and used components in trailer manufacture. When new materials are used in the assembly of a trailer, the trailer will be considered newly manufactured for purposes of paragraph (a) of this section, the application of the requirement s of this chapter, and the Act, unless, at a minimum, the trailer running gear assembly (axle(s), wheels, braking and suspension) is not new, and was taken from an existing trailer--

(1) Whose identity is continued in the reassembled vehicle with respect to the Vehicle Identification Number; and

(2) That is owned or leased by the user of the reassembled vehicle.

ID: nht94-7.18

DATE: March 28, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Thomas D. Turner -- Manager, Engineering Services, Blue Bird Body Company

TITLE: None

ATTACHMT: Attached to letter dated 2/21/94 from Thomas D. Turner to John Womack (OCC 9719)

TEXT:

This responds to your letter of February 21, 1994, requesting further clarification of the requirements of S5.5.3(c) of Standard No. 217, Bus Emergency Exits and Window Retention and Release (as amended at 57 FR 49413; November 2, 1992). Section S5.5.3(c) states that "(e)ach opening for a required emergency exit shall be outlined around its outside perimeter with a minimum 3 centimeters wide retroreflective tape." *1 Your letter referenced our July 7, 1993 letter to you in which we stated that S5.5.3(c) permits interruptions in the tape necessary to accommodate curved surfaces and functional components. You requested confirmation "that retro-reflective tape around the perimeter of the rear of a school bus can be used to satisfy the requirements of S5.5.3(c)."

I cannot interpret the requirements of S5.5.3(c) as you request, since for many, if not most, designs the nearest possible location will be closer than the perimeter of the bus. While we appreciate your concerns about durability if numerous cuts or notches are made to accommodate rivets, our July 7 letter stated that manufacturers have the option of placing the retroreflective tape immediately adjacent to the rivets, rather than over the rivets. As an example, from the illustrations you enclosed, it appears that it may be possible to apply retroreflective tape outside the rivets adjacent to the lower portions of the door. Thus, that would be the nearest possible location, rather than the perimeter of the bus itself. I note, however, that the illustrations do not provide sufficient detail of all obstructions for us to determine the nearest possible location for each design.

I also note that your letter stated in support of your request that all school buses are required to have a rear emergency exit. While this is true, the type of emergency exit will vary and retroreflective tape at the perimeter of the exit would allow rescuers to immediately know the precise location of the exit. Moreover, retroreflective tape at the perimeter would enable rescuers to immediately know which type of exit is in this location. This information could be vitally important. Because push-out windows are not required to have a means of releasing the exit from outside the bus (S5.3.3.2), this information would allow rescuers to quickly determine that they should move to the sides of the bus to locate an exit they can open.

Your letter asked the agency to treat it as a petition for rulemaking if we did not interpret the standard as you requested. You will be notified of our decision to grant or deny your petition.

I hope you find this information helpful. If you have any other questions, please contact us at this address or by phone at (202) 366-2992.

*1 The July 7, 1993 letter also stated that the agency planned to issue a correction notice of the November 2, 1992 rule that would specify a minimum size of 2.5 cm for the tape. This notice has not yet been published. Until the correction is issued, NHTSA will not take enforcement measures regarding tape size against a manufacturer who uses 1 inch wide retroreflective tape.

ID: nht94-8.26

DATE: February 7, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Cheryl Graham -- District Manager, Northeast Region, ARI

TITLE: None

ATTACHMT: Attached to letter dated 11/10/93 from Cheryl Graham to Chief Counsel's Office, NHTSA (OCC-9345)

TEXT:

We have received your letter of November 10, 1993, asking about the permissibility of aftermarket installation of an auxiliary pair of stop lamps "at each side of the rear window."

by way of background information the National Highway Traffic Safety Administration (NHTSA) issues Federal motor vehicle safety standards under the authority of the National Traffic and Motor Vehicle Safety Act (Safety Act). Under that Act, the sole restraint upon modifications to vehicles in use is that, if performed by a manufacturer, distributor, dealer, or motor vehicle repair business, the modifications must not "knowingly render inoperative, in whole or in part, any device or element of design installed on...a motor vehicle in compliance with an applicable Federal motor vehicle safety standard...." (15 U.S.C. 1397(a)(2)(A)).

In NHTSA's view, if the modifications tend to impair the safety effectiveness of the "device or element of design," then, at the minimum, a partial inoperability may have occurred within the meaning of the statutory prohibition. The question raised by your letter, therefore, is whether the installation of the auxiliary stop lamps in that location would impair the effectiveness of the three original equipment stop lamps.

NHTSA decided to require the center highmounted stop lamp in addition to the then-existing original equipment two-lamp stop lamp system following research which indicated that a three-lamp system of this configuration was demonstrably more effective in preventing rear end crashes than other rear end lighting systems that were tested, and considerably lower in cost. Included in the testing was a four-lamp system which incorporated two lamps at each side of the rear window, but no tests were conducted on the five-lamp system you describe.

The reasons for the better performance of the three-lamp system are unclear, but the triangular lighting array proved to be more effective than the trapezoidal four-lamp system (and more effective than a system tested which separated the usual stop lamp from the tail lamp).

Your customer appears to believe that the ability of following drivers to avoid rear end crashes is enhanced by a five-lamp stop lamp system. On the other hand, your proposed system, by incorporating the two lamps at each side of the rear window, would appear to change the lighting array. We cannot say that the five-lamp system would either enhance or detract from safety. Thus, we cannot find that the additional lamps would "render inoperative" the original equipment three-lamp system, and it would be permissible under the regulations of this agency. However, the

permissibility of such a modification would be determinable under State law. We are unable to advise you on the laws of the various States and suggest that you write the American Association of Motor Vehicle Administrators for an interpretation. Its address is 4600 Wilson Boulevard, Arlington, VA 22203.

You have also asked "if the work is done improperly and results in an accident, where does the liability lie?" This question is a matter of state law, and we suggest that you consult a local attorney concerning it.