By John S. McClenahen When William D. Zollars testifies for Yellow Corp. and the National Coalition on Ergonomics July 16 at the first of three planned U.S. Labor Dept. "town meetings" he will support a mandatory federal ergonomics rule. "We're O.K." with a reasonable new rule that's based on "good science," Zollars says. In contrast, the rule OSHA implemented last year and which was repealed by Congress earlier this year was "squishy" and not based on good science, contends Zollars, the chairman, president, and CEO of Yellow, based in Overland Park, Kans. He believes a voluntary ergonomics rule aimed at injury prevention would not work. "It's hard for me to understand how a voluntary rule would work and be effective." Zollars' first choice is to incorporate a new ergonomics rule into the existing workers' compensation structure.