Interpretation ID: nht91-7.29

DATE: December 4, 1991

FROM: Paul Jackson Rice -- Chief Counsel, NHTSA

TO: Michael D. Incorvaia -- Manufacturing Engineering Manager, Wagner Lighting

TITLE: None

ATTACHMT: Attached to letter dated 11-12-91 from Paul Jackson Rice to Michael D. Incorvaia (Std. 102); Also attached to letter dated 7-3-91 from Michael D. Incorvaia to NHTSA Office of Chief Counsel

TEXT:

This responds to your telephone call to Taylor Vinson of this Office on November 21, 1991, in which you pointed out that our letter to you of November 12, 1991, appeared to conflict with paragraph S5.5.6 of Standard No. 108.

You had asked whether Standard No. 108's requirement for an outage indication for turn signal lamps would be met by a new design developed by your company. Our letter of November 12 informed you that motor vehicles must now be manufactured to meet either SAE Standard J588 NOV84, Turn Signal Lamps for Use on Motor Vehicles Less Than 2032 mm in Overall Width, or SAE Standard J1395 APR95, Turn Signal Lamps for Use on Motor Vehicles 2032 mm or More in Overall Width, and that the outage indication requirement of the previously effective SAE Standard J588e was not adopted in either of the SAE standards. Therefore, under Standard No. 108, Wagner Electric was free to adopt such change in flash rate as its new design may call for.

Your telephone call pointed out that paragraph S5.5.6 of Standard No. 108 continues to require, in pertinent part, that "Failure of one or more turn signal lamps to operate shall be indicated in accordance with SAE Standard J588e, Turn Signal Lamps, September 1970 . . . ." That is correct, and I regret that you were misinformed on this point. Paragraph 4.5 of SAE Standard J588e states, in pertinent part, that "failure of one or more turn signal lamps to operate should be indicated by . . . a significant change in the flashing rate of the illuminated indicator." Electronic flashers available today provide a "significant change" in flash rate by doubling it as an outage indication. Wagner Lighting has developed a lamp outage indication that will remain within the performance parameters of Standard No. 108, but provide an outage flash rate that appears to be slightly less than 50% greater than that of normal operation. However, there will be "a recognized change in flashing rate." You have asked whether these changes may be regarded as "significant" within the meaning of SAE J588e.

The agency has never before addressed this provision in SAE J588e. The provision of an outage rate that is twice that of normal flasher performance represents industry's interpretation of the word "significant", and not NHTSA's. The intent of paragraph 4.5 is to call the attention of the vehicle operator to the failure of a signal lamp to operate. You have represented that the change in flash rate in the Wagner design is one that can be "recognized." Assuming that this is true then the change in flash rate can be viewed as one that is "significant" within

the meaning of SAE J588e.

However, perceiving that a change in flash rates has occurred, and understanding its meaning are different matters. If a double flash rate has been the industry norm, one to which motorists have become accustomed, the meaning of a flash rate that differs from normal operation but is less than double that of ordinary operation might not be readily apparent to the vehicle operator. Therefore, it might be in the interest of safety for operator's manuals and flasher packages to indicate the flash rates that will indicate normal and outage operation.