Interpretation ID: nht95-2.38

TYPE: INTERPRETATION-NHTSA

DATE: April 14, 1995

FROM: Lance Tunick -- Vehicle Science Corporation

TO: Taylor Vinson, Esq. -- Office of the Chief Counsel, NHTSA

TITLE: Re: Request for interpretation of FMVSS 108

ATTACHMT: ATTACHED TO 5/3/95 LETTER FROM JOHN WOMACK TO LANCE TUNICK (A43; Std. 108)

TEXT: Dear Mr. Vinson:

This letter requests an interpretation of a portion of SAE J586 (Feb. 84) installation requirements for rear stop lamps (section 5.4.1), as incorporated by reference in FMVSS 108, Table III.

More specifically, this request concerns the visibility requirements for rear stop lamps. The referenced SAE section states that "to be considered visible, the lamp must provide an unobstructed view of the outer lens surface of at least 12.5 square cent imeters measured at 45 degrees to the longitudinal axis of the vehicle." (Emphasis added.) "Outer lens surface", however, is not defined either in the SAE materials or in FMVSS 108.

We believe that "outer lens surface" when used in the above section of J586 means "light emitting surface" as defined in SAE J387.

Please confirm the agency's definition of "outer lens surface" as used in the visibility requirement in SAE J586 (Feb. 84).

Given testing and production deadlines, we kindly request as prompt an answer as possible.

Thank you for your kind attention.