Interpretation ID: nht95-2.91

TYPE: INTERPRETATION-NHTSA

DATE: May 19, 1995

FROM: Milford R. Bennett -- Director, Safety Affairs, Safety & Restraints Center, General Motors; Signature by F. Laux

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

TITLE: Subject: Request for FMVSS 205 Interpretation; USG 3183

ATTACHMT: ATTACHED TO 9/19/95 LETTER FROM JOHN WOMACK TO MILFORD BENNETT (A43; REDBOOK 2; STD. 205)

TEXT: Dear Mr. Womack:

The purpose of this letter is to request an interpretation of FMVSS 205. Specifically, General Motors seeks the agency's concurrence that a vehicle equipped with a particular rear window sunshade meets the light transmissibility requirements of FMVSS 205 .

General Motors plans to offer a rear window sunshade in a near-future Cadillac model. The sunshade is a screen-like device that significantly reduces the light and heat load entering through the backlite. In its raised position, the sunshade covers app roximately 90% of the backlite area, and the light transmissibility through the combined backlite and sunshade is less than 70%. In its retracted position, the sunshade is stowed in the panel shelf area below the backlite, such that no portion of the bac klite is obscured. A driver operated switch on the instrument panel is used to electrically raise and lower the sunshade.

FMVSS 205 requires a minimum of 70% light transmissibility through glazing that is requisite for driving visibility. The agency has historically interpreted the backlite of passenger cars to be requisite for driving visibility. General Motors seeks the Chief Counsel's interpretation that the proposed sunshade comports with the transmissibility requirements of FMVSS 205. Our reasons for believing that a vehicle equipped with the sunshade would continue to comply with FMVSS 205 are summarized as follow s:

* The rear window sunshade would have no adverse effect on motor vehicle safety. As with conventional windshield sunvisors, drivers can be expected to utilize the sunshade in a way that will maximize, rather than diminish, driving safety and comfort. Wi th the sunshade in its raised position, trailing vehicles and other objects are readily visible through the screen mesh. Driver and passenger side outside rearview mirrors further provide for rearward visibility, comparable to other passenger carrying v ehicles (light trucks, vans, multipurpose passenger vehicles) which are not required by FMVSS 205 to have 70% light transmittance in the backlite area.

* The sunshade is not glazing material, nor is it in contact with glazing material. FMVSS 205 states that: "This standard specifies requirements for glazing materials for use in motor vehicles and motor vehicle equipment."

* The rear window sunshade is fully analogous to conventional windshield sunvisors. In both cases, the driver-selectable device can be positioned in a way that reduces effective transmissibility below 70%, and then easily stowed when not needed to resto re full transmittance.

* There is a well established international precedent for rear window sunshades. European and Japanese regulatory authorities have explicitly recognized and accepted these devices.

General Motors is aware of previous Chief Counsel interpretations stating that the transmissibility requirements of FMVSS 205 must be met with a rear window sunscreen in position. (Reference Ms. Erika Jones letter to Mr. T. E. McConnell dated September 22, 1986, and Ms. Erika Jones letter to Ms. Susan B. House dated December 22, 1985.) We believe there is a critical distinction between the products the agency has previously commented on and the rear window sunshade GM contemplates. Specifically, the e arlier products were apparently tinting materials applied to the backlite, or shade devices that physically contacted the backlite via attaching hardware. By virtue of being in physical contact with the backlite, these earlier sunscreening products coul d be interpreted as being part of the backlite. The rear window sunshade GM plans to install will not be attached to the backlite in either the raised or stowed position, and therefore is clearly not part of the backlite glazing subject to FMVSS 205.

We would appreciate a favorable response at the agency's earliest convenience. In order to accommodate our product plans for the sunshade device, we would like to obtain a response by July, 1995, if possible. If there is any additional information we ca n provide to help expedite the agency's review, please contact Mr. Philip Horton (810-947-1738), Mr. Richard Humphrey of our Washington office (775-5071), or me (810-947-0149).

Thank you.