Jan 26, 2011 9:27 AM

The American Trucking Associations’ advance seasonally adjusted (SA) For-Hire Truck Tonnage Index increased 2.2% in December 2010 after falling a revised 0.6% in November. The latest improvement put the SA index at 111.6 (2000=100) in December, which was the highest level since September 2008.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 107.2 in December, down 1% from the previous month.

Compared with December 2009, SA tonnage climbed 4.2%, which was higher than November’s 3.3% year-over-year increase. For all of 2010, tonnage was up 5.7% versus 2009. In 2009, the index plunged 8.7%.

ATA Chief Economist Bob Costello said December’s improvement fits well with the see-saw pattern many carriers are reporting.

“Fleets continue to tell me that freight volumes are very choppy—up one week, but down the next,” he said. “That is a trend that is likely to continue this year as the economy is not growing across the board yet.”

Still, Costello said it was a positive sign for the economy that SA tonnage reached the highest level in 27 months. “I continue to expect truck freight tonnage to grow modestly during the first half of 2011 and accelerate in the later half of the year into 2012,” he said.

Trucking serves as a barometer of the US economy, representing 68% of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods. Trucks hauled 8.8 billion tons of freight in 2009. Motor carriers collected $544.4 billion, or 81.9% of total revenue earned by all transport modes.