Interpretation ID: nht88-4.53

TYPE: INTERPRETATION-NHTSA

DATE: 12/30/88 EST

FROM: ERIKA Z. JONES -- NHTSA CHIEF COUNSEL

TO: C. I. NIELSEN III -- VICE PRESIDENT/GENERAL SALES MANAGER, WESBAR CORPORATION

TITLE: NONE

ATTACHMT: MEMO DATED 11-11-88, TO ERIKA 2. JONES, FROM C.I. NIELSEN III -- WESBAR, OCC-2789.

TEXT: This is in reply to your letter of November 11, 1988, asking for an interpretation of Motor Vehicle Safety Standard No. 108. Specifically, you find unclear the "minimum square inches required of a turn signal lens for a trailer/vehicle, 80" or more in o verall with, using a single compartment lamp assembly".

As you stated, the applicable standard is SAE J588e Turn Signal Lamps, September 1970. This standard does not set minimum area requirements per se for turn signal lenses, but it does specify minimum requirements for "effective projected luminous areas" o f turn signal lamps. With respect to a single compartment turn signal lamp, section 3.2 of J588e requires this area, when measured on a plane at right angles to the axis of the lamp, to be at least 8 square inches for a rear lamp, and at least 3.5 squar e inches for a front lamp.

As you are probably aware, on September 9 of this year the agency proposed adopting SAE J1395 APR85 Turn Signal Lamps for Use on Motor Vehicles 2032mm or More in Overall Width. Its section 5.3.2 requires "the functional lighted lens area of a single lam p" to be at least 75 square centimeters (12 square inches). The agency is currently reviewing the comments received on the proposal.

I hope that this clarifies the matter for you.