Thanks to rising retail rates and factory output, American Trucking Associations’ advanced seasonally adjusted For-Hire Truck Tonnage Index rose 0.6% in January after increasing 0.9% in December.

In January, the index equaled 115.5 compared with 114.9 in December.

“January’s gain was the sixth straight totaling 4.4%,” said ATA Chief Economist Bob Costell in a press release. “The index, which is dominated by contract freight with only small amounts of spot market truck freight, is off 3.9% from the all-time high in August 2019 and only 1.5% below March 2020 when the pandemic hit.”

Compared with January 2021, the index increased 1.2%, which was the fifth straight year-over-year gain. In December, the index was up 1.5% from a year earlier. In 2021, compared with the average in 2020, tonnage was up 0.3%. In 2020, tonnage was off 4% compared with 2019.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 109.2 in January, 4.3% below the December level (114.1). In calculating the index, 100 represents 2015.

Trucking serves as a barometer of the U.S. economy, representing 72.5% of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods. Trucks hauled 10.23 billion tons of freight in 2020. Motor carriers collected $732.3 billion, or 80.4% 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.