The American Trucking Associations' advance seasonally adjusted (SA) For-Hire Truck Tonnage Index increased for the sixth time in the last seven months, gaining another 0.9 percent in April. This followed a 0.4 percent increase in March. The latest improvement put the SA index at 110.2 (2000=100), which is the highest level since September 2008. Over the last seven months, the tonnage index grew a total of 6.5 percent.

The not seasonally adjusted index, which represents the change in tonnage actually hauled by the fleets before any seasonal adjustment, equaled 111.3 in April, down 4.4 percent from the previous month.

Compared with April 2009, SA tonnage surged 9.4 percent, which was the fifth consecutive year-over-year gain and the largest increase since January 2005.' Year-to-date, tonnage is up 6 percent compared with the same period in 2009.

ATA Chief Economist Bob Costello said that the latest tonnage reading fits with a sustained economic recovery. 'Truck tonnage volumes continue to improve at a solid, yet sustainable, rate. Tonnage is being boosted by robust manufacturing output and stronger retail sales.' Costello also reiterated a statement from last month's release, saying: 'For most fleets, freight volumes feel better than reported tonnage because the supply situation, particularly in the truckload sector, is turning quickly.'

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 68 percent of tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods.

Trucks hauled 8.8 billion tons of freight in 2009. 'Motor carriers collected $544.4 billion, or 81.9 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.