American Trucking Associations’ advanced seasonally adjusted (SA) For-Hire Truck Tonnage Index decreased 1.5 percent in June after falling 1 percent in May. In June, the index equaled 111.6 (2015=100) compared with 113.3 in May.

“Tonnage has definitely flattened out, on average, over the last six to nine months,” said ATA Chief Economist Bob Costello. “The good news is that it remains slightly above 2020 levels.

“Supply chain issues are likely putting some downward pressure on tonnage,” he said. “But it is also likely that tonnage isn’t growing as much as it could because of industry-specific supply constraints. This index is dominated by contract freight, and the for-hire truckload carriers have seen their tractor counts fall because they are having difficulty finding qualified drivers. It is difficult to move more tonnage with less equipment, which is why we are seeing strong volumes in the spot market as shippers scramble to get loads moved.”

May’s reading was revised down slightly to -1 percent from its June 22 press release.

Compared with June 2020, the SA index rose 0.5 percent, which was preceded by a 3.3 percent year-over-year increase in May. Year-to-date, compared with the same six months in 2020, tonnage is up 0.3 percent.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 116.2 in June, 2.4 percent above the May level (113.4). 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.