JACKSONVILLE, Fla. (AP) â¿¿ Short line and regional freight railroad operator RailAmerica Inc. said Wednesday its August carloads rose 3.6 percent from a year earlier, mostly due to higher shipments of metals, chemicals and minerals. Shipments rose in half of the company's 12 commodity groups. The largest declines were in coal, waste and scrap materials, and motor vehicles. The company expects carloads to grow about 5 percent in the third quarter, which ends this month, compared with the same period in 2009. RailAmerica operates 40 individual railroads with about 7,400 miles of track in 27 U.S. states and three Canadian provinces. Railroads are indicators of broader economic health because they move so many raw materials and products used by consumers every day.