Several strategies enabled Heartland Express Inc. to keep fuel costs under control in the first quarter of 2011, the North Liberty-based trucking company said in a quarterly report filed May 6 with the Securities and Exchange Commission.

“The U.S. average price of diesel fuel increased 28.2 percent from approximately $2.85 per gallon to approximately $3.66 per gallon, and the company’s miles increased in the three months ended March 31, 2011, compared to the same period of 2010,” Heartland reported. “However, fuel expense, net of fuel surcharge revenues, only increased 14.1 percent.”

The company said factors mitigating the effects of higher fuel prices included “strategic fueling of our trucks whether it be terminal fuel or over-the-road fuel, reduction of tractor idle time, controlling out-of-route miles, increased fuel economy through new tractors acquired in 2008 through (the) first quarter of 2011, and to a lesser extent fuel hedging.”

Heartland also noted that “current freight volumes are still below volumes experienced prior to the recent recession,” but added that the rates it charged for hauling freight increased in 2010 and into the first quarter of 2011, and said management expects rates to continue upward for the rest of the year.