The American Trucking Associations' advanced seasonally adjusted (SA) For-Hire Truck Tonnage Index jumped 6.8 percent in December after rising 0.3 percent in November 2011. The latest gain put the SA index at 124.5 (2000=100) in December, up from the November level of 116.6.
For all of 2011, tonnage rose 5.9 percent over the previous year – the largest annual increase since 1998. Tonnage for the last month of the year was 10.5 percent higher than December 2010, the largest year-over-year gain since July 1998. November tonnage was up 6.1 percent over the same month last year. The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 116.4 in December, which was 0.8 percent above the previous month.
"While I'm not surprised that tonnage increased in December, I am surprised at the magnitude of the gain," ATA Chief Economist Bob Costello said. Costello noted that it was the largest month-to-month increase since January 2005.
"Not only did truck tonnage increase due to solid manufacturing output in December, but also from some likely inventory restocking. Inventories, especially at the retail level, are exceedingly lean, and I suspect that tonnage was higher than expected as the supply chain did some restocking during the month." he said.
Note on the impact of trucking company failures on the index: Each month, ATA asks its membership the amount of tonnage each carrier hauled, including all types of freight. The indexes are calculated based on those responses. The sample includes an array of trucking companies, ranging from small fleets to multi-billion dollar carriers. When a company in the sample fails, we include its final month of operation and zero it out for the following month, with the assumption that the remaining carriers pick up that freight. As a result, it is close to a net wash and does not end up in a false increase. Nevertheless, some carriers are picking up freight from failures and it may have boosted the index. Due to our correction mentioned above however, it should be limited.
Trucking serves as a barometer of the U.S. economy, representing 67.2 percent of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods. Trucks hauled 9 billion tons of freight in 2010. Motor carriers collected $563.4 billion, or 81.2 percent 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.