The American Trucking Associations' (ATA) advanced seasonally adjusted for-hire truck tonnage Index fell four per cent in January after surging 6.4 per cent in December 2011. The latest contraction put the SA index at 119.4 (2000=100), down from December's record level of 124.4.
The ATA recently revised the seasonally adjusted index back five years as part of its annual revision. For all of 2011, tonnage rose 5.8 per cent, slightly lower than the 5.9 per cent previously reported, and matched 2010's gain of the same magnitude. The index increased 3. per cent from January 2011.
The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 112.1 in January, which was 3.5 per cent below the previous month.
“Last month I said I was surprised by the size of the gain in December. Today, I'm not surprised that tonnage fell on a seasonally adjusted basis in January simply due to the fact that December was so strong,” ATA Chief Economist Bob Costello explains while noting that December's increase was the largest month-to-month gain since January 2005.
The ATA is the largest national trade association for the trucking industry. Each month, it asks its membership the amount of tonnage each carrier hauled, including all types of freight and has been doing so since the 1970s. 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.