American Trucking Associations' advanced seasonally adjusted (SA) For-Hire Truck Tonnage Index jumped 6.3% in October to 119.9 from September's mark of 112.8.

"After slowing at the end of the third quarter, truck freight surged in October," said ATA Chief Economist Bob Costello. "Last month's strength was due, at least in part, to strong import numbers, especially on the West Coast. This is likely a pull ahead of imports as shippers try to take delivery of goods before January 1 when tariffs on a large list of goods China increases from 10% to 25%."

September's change over the previous month was revised up to +0.1% (-0.8% was originally reported in our press release on October 23).

Compared with October 2017, the SA index increased 9.5%, up from September's 3.8% year-over-year increase. Year-to-date, compared with the same period last year, tonnage increased 7.3%.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 124.4 in October, which was 11.8% above the previous month (111.2). In calculating the index, 100 represents 2015.

Trucking serves as a barometer of the U.S. economy, representing 70.2% of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods. Trucks hauled 10.77 billion tons of freight in 2017. Motor carriers collected $700.1 billion, or 79.3% 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.