The American Trucking Associations' advance seasonally adjusted For-Hire Truck Tonnage Index increased 2.8% in June after decreasing a revised 2.0% inMay 2011. May's drop was slightly less than the 2.3% ATA reported onJune 27, 2011. The latest gain put the SA index at 115.8 (2000=100) in June, up from the May level of 112.6 and the highest sinceJanuary 2011.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 122.3 in June, which was 5.3% above the previous month.

Compared withJune 2010, SA tonnage jumped 6.8%, the largest year-over-year gain sinceJanuary 2011. In May, the tonnage index was 3% above a year earlier.

"Motor carriers told us that freight was strong in June and that played out in the data as well," ATA Chief EconomistBob Costellosaid. Tonnage recovered all of the losses in April and May when the index contracted a total of 2.6%.

"After growing 5.5% in the first half of the year from the same period last year, the strength of truck tonnage in the second half will depend greatly on what manufacturing output does," Costello noted. "If manufacturing continues to grow stronger than GDP, I fully expect truck freight to do the same."