by Calculated Risk on 3/22/2011 12:06:00 PM

This is one of several transportation indexes I follow ...

From the American Trucking Association: ATA Truck Tonnage Index Fell 2.9% in February

The American Trucking Associations’ advance seasonally adjusted (SA) For-Hire Truck Tonnage Index decreased 2.9% in February after increasing a revised 3.5% in January 2011. ... In January, the SA index equaled 116.6. During December 2010 and January 2011, the SA tonnage index jumped a total of 6.1%.
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ATA Chief Economist Bob Costello said that the winter storms in February probably played a role in the latest reduction and that he wasn’t concerned about the decrease. “Tonnage is not going to increase every month and in general I’m very pleased with freight volumes early this year.” Costello also stated that the anecdotal reports from motor carriers are very encouraging. “I’m hearing a significant amount of positive news from fleets and that the largest concern continues to be the price of diesel fuel, not freight levels.”
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Trucking serves as a barometer of the U.S. economy, representing 68% of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods.

Click on map for graph gallery.

This graph from the ATA shows the Truck Tonnage Index since Jan 2007.

This decline followed two sharp increases, so it isn't that concerning. The largest concern for truckers is oil prices, not freight levels - and high oil prices are a key risk for the economy, especially with gasoline prices hitting $4 per gallon in some areas.