American Trucking Associations' advanced seasonally adjusted For-Hire Truck Tonnage Index slipped 0.1% in February, following a 2.9% increase during January. (January's index was unchanged from our press release on February 21, 2017.) In February, the index equaled 138.7 (2000=100), down from 138.9 in January. The all-time high was 142.7 in February 2016.

Compared with February 2016, the SA index decreased 2.8%. In January, the index rose 2.6% on a year-over-year basis. Year-to-date, compared with the same two months in 2016, the index is off 0.1%. For all of 2016, tonnage was up 2.5%.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 125.5 in February, which was 4.6% below the previous month (131.7).

"February's numbers, especially the year-over-year drop, might surprise some as several other economic indicators were positive in February," said ATA Chief Economist Bob Costello. "However, I'm not worried about the decline from February last year as it was really due to very difficult comparisons more than anything else: February 2016 was abnormally strong.

"Looking ahead, signs remain mostly positive for truck tonnage, including lower inventory levels, better manufacturing activity, solid housing starts, good consumer spending, as well as an increase in the oil rig count – all of which are drivers of freight volumes" he said.

Trucking serves as a barometer of the U.S. economy, representing 70.1% 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 2015. Motor carriers collected $726.4 billion, or 81.2% of total revenue earned by all transport modes.

ATA calculates the tonnage index based on surveys from its membership and has been doing so since the 1970s. This is a preliminary figure and subject to change in the final report issued around the 10th day of the month. The report includes month-to-month and year-over-year results, relevant economic comparisons and key financial indicators.