The American Trucking Associations' Truck Tonnage Index rose 0.6% in February, marking the fourth straigth month of increases -- which hasn't happened since late 2011.

ATA's dvanced seasonally adjusted (SA) For-Hire Truck Tonnage Index rose 0.6% in February after increasing 1% in January. (The 1% gain in January was revised down from a 2.4% increase ATA reported on February 19.)

Over the last four months, tonnage gained a total of 7.7%.

In February, the SA index equaled 123.6 (2000=100) versus 123.0 in January. The highest level on record was December 2011 at 124.3.

"Fitting with several other key economic indicators, truck tonnage is up earlier than we anticipated this year," ATA Chief Economist Bob Costello said. "While I think this is a good sign for the industry and the economy, I'm still concerned that freight tonnage will slow in the months ahead as the federal government sequester continues and households finish spending their tax returns.

"A little longer term, I think the economy and the industry are poised for a more robust recovery." 

Compared with February 2012, the SA index was up a solid 4.2%, just below January's 4.6% year-over-year gain. Year-to-date, compared with the same period in 2012, the tonnage index is up 4.4%. In 2012, tonnage increased 2.3% from 2011.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 113.5 in February, which was 5.5% below the previous month (120.1).