($ millions)
| 1999 | 2000 | 2001 | 2002 | 2003 | |
|---|---|---|---|---|---|
| Truck | 52,998 | 54,659 | 47,196 | 43,732 | 45,753 |
| Rail | 16,990 | 14,473 | 10,497 | 8,786 | 9,127 |
| Pipeline | 404 | 566 | 2,023 | 2,302 | 3,949 |
| Other and unknown | 454 | 433 | 762 | 269 | 541 |
| Total | 70,847 | 70,132 | 60,478 | 55,089 | 59,369 |
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, Transborder Surface Freight Data, 1999-2003.