ARLINGTON, VA — The American Trucking Associations’ (ATA) advanced seasonally adjusted (SA) For-Hire Truck Tonnage Index saw the largest month-to-month gain in June  when it increased 1.2 percent after falling 1 percent in May. (ATA initially reported that May’s drop was 0.7 percent.)

The gain increased the SA index to 119.0, up from May’s level of 117.5.

Compared with June 2011, the SA index was 3.2 percent higher, the smallest year-over year increase since March 2012. Year-to-date, tonnage was up 3.7 percent.

“June’s increase was a pleasant surprise, but the lower year-over-year gain fits with an economy that has slowed,” said Bob Costello, chief economist for the ATA. “Manufacturing output was strong in June, which helped tonnage levels.”

For the second quarter, the SA index was off 0.8 percent from the previous quarter, which was the first decrease in a year, but compared with the second quarter in 2011, the index was up 3.5 percent.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 123.0 in June, which was 0.9 percent below the previous month.

Costello said he’s still concerned about businesses sitting on cash instead of hiring more workers or spending it on capital, both of which would help the economy and tonnage. Costello lowered his tonnage outlook for 2012 to the 3 to 3.5 percent range due to recent economic weakness.