ByJohn S. McClenahen Every now and then the U.S. economy is like the traffic light on a multilane road: It displays more than one signal at the same time. Manufacturing, the sector of the economy that was clobbered during last year's recession, is seeing a couple of economic green lights. Factory inventories, excluding semiconductors, were down 0.3% from February to an end-of-March total of $1.12 trillion, says the U.S. Commerce Department's Bureau of the Census. Dramatizing just how much inventory overhang has been cut back during the past 12 months, the March 2002 dollar figure is 5.9% below March 2001's level. Meanwhile, manufacturing output increased 0.3% in April of this year, to its highest level since August 2001, reports the U.S. Federal Reserve Board. Also in April, the operating rate of U.S. factories advanced to 73.9%, the highest it has been this year. A caution light seems to be coming from April's Consumer Price Index, however. The U.S. Labor Department's Bureau of Labor Statistics reports the seasonally adjusted CPI rose 0.5% last month, one-tenth of a percentage point higher than most economists expected and two-tenths of a percentage point higher than March's 0.3%. Pushed mainly by a 9.4% increase in the price of petroleum-based energy, April's CPI rise was the biggest this year.