Interpretation ID: deyoung.ztv

Mr. Jack W. DeYoung
Tumbleweed Trucks, Inc.
318 Kwanzan Drive
Lynden, WA 98264

Dear Mr. DeYoung:

This responds to your letter dated November 15, 2002, and your letter of November 19, 2002, which responded to my letter to you dated November 14, 2002. I regret that your letters were misplaced and that you had to contact us several times.

The subject matter of our correspondence is the flash rate of hazard warning signal flashers. Your letter of November 15 (written before you had received my November 14 reply to your letter of October 18) stated your understanding that the agencys interpretation to Robert A. Belcher in 1980 was applicable to your flasher as well. Mr. Belcher had developed a dual mode hazard flasher, which flashed at a constant rate in one mode. In the other, or "distress," mode, the flasher alternated between a short flash and a long flash to simulate the international distress signal "S.O.S."We understood that the flash rate of the emergency distress signal mode would be 71 flashes per minute, and we informed Mr. Belcher that if it maintained this flash rate and met other requirements of J945, "it should qualify" (our letter of October 30, 1980). We further informed Representative Norm Shumway on July 30, 1984, with respect to Mr. Belchers device, that "We find nothing in Standard No. 108 that precludes a dual mode flash for hazard flashers, provided that the flash rates chosen [comply], adding that "current flashers, of course, operate at a constant rate." We do not appear to have provided any other interpretations regarding flashers operating at a rate other than constant.

On November 19, you replied to my letter of November 14, stating that your system was designed to produce 120 cycles per minute and that you did not agree with our calculations which indicated a rate of more than 120 cycles per minute. I would note here that, in contrast to the Belcher system which operated at a flash rate of only 71 per minute, the 120 flashes per minute that you ascribe to your system is the maximum that the standard permits.

As I mentioned in my letter of November 14, SAE Recommended Practice J945, "Vehicular Hazard Warning Signal Flasher," February 1966, is incorporated by reference in Standard No. 108 as the Federal requirement for flashers. Paragraph 3 of SAE J945 specifies that the "flashing rate . . . shall be measured after the flashers have been operating for a minimum of five consecutive cycles and shall be an average of at least three consecutive cycles." (our emphasis). You are correct in your remark that in our calculation we took "an arithmetic average of three flash rates without considering the amount of time each uses," and that this was an "unweighted average." We do not read the word "average" in SAE J945 as meaning anything other than an arithmetic average. Thus, in our opinion, compliance with Standard No. 108 requires that the flash rate be met over an arithmetic average of any number of three or more consecutive cycles that may be chosen after a minimum of five consecutive cycles have occurred since activation of the signal. Thus, your flash rate increases to 144.3 per minute if we measure the rate over 4 cycles, and to 148.7 per minute if we measure the rate over 5 cycles.

Your letter of November 15 also asked for confirmation that it would be permissible for a truck or bus owner to install your flasher even if it did not meet Standard No. 108s flash rate requirements. Paragraph S5.8.1 of Standard No. 108 requires that lighting equipment manufactured to replace original equipment be designed to conform to the standard. We regard your device as a flasher intended to replace a flasher manufactured in accordance with SAE J945. Thus, its flash rate must be within the parameters specified in SAE J945. The flash rate exceeds the maximum rate specified. Under 49 U.S.C. 30112(a), a person shall not manufacture, sell, offer for sale, deliver for introduction in interstate commerce, or introduce in interstate commerce any item of motor vehicle equipment that does not comply with an applicable Federal motor vehicle safety standard and is not certified as meeting that standard. Under 49 U.S.C. 30165, a person who violates Section 30112(a) is liable for a civil penalty of up to $5,000 for each violation, up to $15,000,000 for a related series of violations. Thus, we do not anticipate that you will manufacture and sell your device, and the question of installation is moot.

If you have any questions, you may contact Taylor Vinson of this Office (202-366-5263).

Sincerely,

Jacqueline Glassman
Chief Counsel

ref:108
d.8/7/03