ARLINGTON, VA – The amount of truck tonnage hauled in the U.S. fell slightly in June, as manufacturing and retail sales also declined, according to the latest survey of carriers by one fleet group.

The American Trucking Associations advanced seasonally adjusted (SA) For-Hire Truck Tonnage Index decreased 0.5% to a level of 131.1, following a revised gain of 0.8% during May.

The all-time high of 135.8 was hit in January of this year.

Compared with June 2014, the SA index increased 1.8%, which is above the 1.5% gain in May.

Year-to-date through June, compared with the same period last year, tonnage was up 3.4%.

“With flat factory output and falling retail sales, I’m not surprised tonnage was soft in June,” said ATA Chief Economist Bob Costello. “I also remain concerned over the elevated inventory-to-sales ratio for retailers, wholesalers, and manufacturers, which suggests soft tonnage in the months ahead until the ratio falls.

During the second quarter, the SA index fell 1.7% from the first quarter but increased 2% from the same quarter in 2014.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 138.2 in June, 4.2% above the previous month’s reading of 132.7/

“I remain hopeful that the inventory correction will transpire this summer. When the correction ends, truck freight, helped by better personal consumption, will accelerate,” Costello said. 

Trucking serves as a barometer of the U.S. economy, according to ATA, representing 68.8% of tonnage carried by all modes of U.S. domestic freight transportation, including manufactured and retail goods.