The snags have affected retailers, distributors and manufacturers, and boosted transportation costs as much as 150 percent.
The tie-ups began early this year. But with shipments poised to rise for the fall and holiday seasons, the snarls are likely to worsen significantly in coming weeks, says Ed Sands, global practice leader in logistics for ICG Commerce, a procurement firm.
"Every direction you go, there is a major challenge you face getting your goods to market in a timely fashion," Sands said.
Shipping, air cargo and trucking companies scaled back capacity and cut prices sharply as sales slowed in the recession.
As demand has picked up this year, carriers' capacity has not kept pace.
The bottlenecks have been most severe for ocean shipments of apparel, electronics and other goods made in Asia, Sands said.