The American Trucking Association's for-hire truck tonnage index fell 2.7 percent in August from July, its largest month-to-month drop since March 2009.
The 2.7 percent decrease in the seasonally adjusted tonnage figures follows a 1.5 percent increase in July from June. For-hire tonnage dropped 1.6 percent in June.
The seasonally adjusted tonnage index climbed 2.9 percent year-over-year, but the decline from July signaled the freight surge truckers enjoyed this spring is ebbing.
The 2.9 percent rise from August 2009 was much smaller than the 7.4 percent year-over-year jump ATA reported in July. Year-to-date, tonnage is up 6.2 percent.
By The Numbers: Cass Freight Index.
The economy, while still growing, is slowing, said ATA Chief Economist Bob Costello.
"We fully anticipate sluggish economic growth for the remainder of this year and the latest tonnage numbers are reflecting that slowdown," Costello said.
The Conference Board's index of leading economic indicators increased 0.3 percent in August, and the private research group is forecasting a slow recovery.
Costello said falling tonnage doesn't necessarily mean a decline in revenue or profit for trucking companies.
"While I'd much rather see better tonnage figures, motor carriers can now do better with small increases in demand since so much supply left the industry during the recession," he said.
-- Contact William B. Cassidy at email@example.com.