American Trucking Associations' advanced seasonally adjusted For-Hire Truck Tonnage Index declined 2.6% in February after rising 1.6% in January. In February, the index equaled 109.2 (2015=100), down from 112.1 in January.

ATA revised the January increase from the originally reported 2.0% to 1.6%.  

Compared with February 2017, the SA index jumped 5.7%, which was below January's 8.4% year-over-year gain, but still well above 2017's annual increase. For all of 2017, the index increased 3.8% over 2016. Year-to-date, compared with the same two months in 2017, tonnage is up 7.1%.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 99.7 in February, which was 6.7% below the previous month (106.8).

"Despite a softer February than January, freight remains robust as exhibited in the year-over-year increase," said ATA Chief Economist Bob Costello. "The drivers of truck freight – personal consumption, factory output and construction – are good, plus the inventory cycle is in favor of motor carriers, so I expect freight tonnage to grow at a decent pace in the months ahead."

Trucking serves as a barometer of the U.S. economy, representing 70.6% of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods. Trucks hauled nearly 10.5 billion tons of freight in 2016. Motor carriers collected $676.2 billion, or 79.8% of total revenue earned by all transport modes.