This chart shows the total tonnage transported by the trucking industry. (Seasonally adjusted; 2000 = 100)
Here is an article on a rebound in trucking from NPR
A couple of things I found surprising:
1. Capacity is tight because a lot of owner operators left the business when things got tight in 2007. Many of these people will not return. Some 1,700 small trucking companies folded just last year. That sent thousands of drivers out of the business, and that wave of failures has swelled even as the freight markets improved.
2. The rise in trucking freight volume has led to a rise in the value of semi-trucks. Previously, when freight conditions were weak, the value of these semi's fell considerably. Now that the values are rising, banks are more likely to repo these trucks because it is easier to sell them.