On the heels of June's revised reduction of 1.6 percent, the American Trucking Associations' advance seasonally adjusted For-Hire Truck Tonnage Index was back up in July

, raising the index from 108.3 (2000=100) in June to 110 in July.

July's tonnage was up 1.5 percent from June and up 7.4 percent over July 2009. The month represented the eighth straight year-over-year gain. So far in 2010, tonnage is up 6.7 percent over the same period of 2009.

Despite the boost in tonnage, ATA Chief Economist Bob Costello said he hasn't changed his outlook for subdued tonnage growth in the months ahead. "The economy is slowing and truck freight tonnage has essentially gone sideways since April 2010."

However, Costello believes tonnage will see moderate gains, on average, for the second half of the year. "After accounting for the reduction in supply over the last few years, even small gains in tonnage will have a larger impact on the industry than in past."

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, was at 109.9 in July, down 5 percent from June.