Truck tonnage rose 1.2% in March following a 1.6% gain in February, according to the American Trucking Associations (ATA).

March's tonnage index grew slightly more than 1.5% compared to March 2006, "marking the first year-over-year increase since June 2006," say ATA officials.

ATA Chief Economist Bob Costello believes the year-over-year increase is a postive sign. "The latest increases... bode well for the industry."

However, he cautions that year-over-year changes "could still fall back into negative territory during some future months. Many motor carriers are telling us anecdotally that April has been filled with starts and stops."