American Trucking Associations' advanced seasonally adjusted (SA) For-Hire Truck Tonnage Index fell 5.4 percent in March after increasing 0.9 percent in February. In March, the index equaled 111.6 (2015=100) compared with 118 in February.

"After increasing a total of 2.6 percent during the three previous months, March's sequential decline was the largest monthly drop since April 2020 during the start of the pandemic," said ATA Chief Economist Bob Costello. "Falling home construction, decreasing factory output and soft retail sales all hurt contract freight tonnage – which dominates ATA's tonnage index – during the month. Despite the largest year-over-year drop since October 2020, contract freight remains more robust than the spot market, which continues to see prolonged weakness."

Compared with March 2022, the SA index decreased 5 percent, which was the first year-over-year decrease since August 2021. In February, the index was up 1.9 percent from a year earlier. During the first quarter, tonnage was 0.6 percent below the same three-month period in 2022.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 117.2 in March, 9.3 percent above the February level (107.2). In calculating the index, 100 represents 2015. ATA's For-Hire Truck Tonnage Index is dominated by contract freight as opposed to spot market freight.

Trucking serves as a barometer of the U.S. economy, representing 72.2 percent of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods. Trucks hauled 10.93 billion tons of freight in 2021. Motor carriers collected $875.5 billion, or 80.8 percent of total revenue earned by all transport modes.