The American Trucking Assns. (ATA) advanced seasonally adjusted For-Hire Truck Tonnage Index increased 2.8% in July, following a revised drop of 0.4% during June. In July, the index equaled 135.0 (2000=100), the second highest level on record. The all-time high of 135.8 was reached in January 2015.Compared with July 2014, the SA index increased 3.7%, which was above the 1.9% gain in June. Year-to-date through July, compared with the same period last year, tonnage was up 3.4%. The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 137.3 in July, which was 0.8% below the previous month (138.4). “After several soft months starting in February, tonnage really snapped back in July,” said ATA chief economist Bob Costello. “July was the single best monthly gain since November 2013.”Costello said a few factors added to July’s strength, including better retail sales, factory output, and housing starts. “However, I remain concerned in the near term about the high level of inventories throughout the supply chain. This could have a negative impact on truck freight volumes over the next few months.” Trucking serves as a barometer of the U.S. economy, representing 68.8% of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods. Trucks hauled just under 10 billion tons of freight in 2014. Motor carriers collected $700.4 billion, or 80.3% 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.