International gains were propelled by continued strength in imports as retail sales and consumer spending improved in Q1 2011. Domestic volumes also continued to increase, with trailer loads rising 7.5% ' the fourth-consecutive quarter of gains for trailers. Most notable is that 53-foot trailer loads posted a substantial 21.7% gain, the best performance for this category since Q1 2005. Rapidly rising diesel fuel prices may have helped shift some over-the-road volume to rail during the quarter.
First Quarter 2011 Intermodal Volume Comparisons
| Equipment Type | 2010 | 2011 | Change |
| Trailers | 383,364 | 412,221 | 7.50% |
| Domestic Containers | 1,034,036 | 1,124,769 | 8.80% |
| All Domestic Equipment | 1,417,400 | 1,536,990 | 8.40% |
| ISO Containers | 1,601,909 | 1,755,301 | 9.60% |
| Total | 3,019,309 | 3,292,291 | 9.00% |
Domestic container volume increased 8.8%, only slightly below Q4 2010's 8.9% rise. Unlike some recent quarters, gains were not driven by transloaded international freight. The most significant domestic container growth came from the Southeast (16.7%), followed by the South Central (15.5%) and the Northeast (14.4%) regions. The Southwest and Western Canada regions ' both centers of international freight transloading by rail ' posted below average increases during Q1 2011.
Intermodal volume forecasts by some analysts project overall gains of 6%'8% in 2011, indicating that this should be a good year for all intermodal markets, especially as year-over-year comparisons bump-up against the strong gains of late 2010.
