From the Journal of Commerce:

The deterioration in truck turn times at the ports of Los Angeles and Long Beach in the past six months was due primarily to near-record container volumes at the ports and a dislocation of chassis. Truck capacity crunch, labor slowdowns and a half-dozen other events were simply irritants that made the problem worse.

“There have been no significant new congestion generators in six months. Record delays are attributable to near-record volume,” said Val Noronha, president of Digital Geographic Research Corp.