| Abbreviation | Definition |
|---|---|
| TRBX | Timken Roller Bearing |
| TRC | Trona Railway |
| TRC | Trona Railway Company |
| TRCL | Tri Rail Coastal Link |
| TRCX | Tri-Rail |
| TRDU | Triad Transport |
| TRDU | Triad Transport Incorporated |
| TRE | Trinity Railway Express |
| TREU | Triest Ag Group,Inc |
| TREX | Tetra Technologies |
| TREX | Tetra Technologies Incorporated |
| TRFU | Trans Freight |
| TRFU | Trans Freight Incorporated |
| TRFZ | Transcontinental Refrigerator Lines |
| TRFZ | Transcontinental Refrigerator Lines Incorporated |
| TRGX | First Union Rail |
| TRGX | Terminal Grain Corporation |
| TRH | Truck Rail Handling |
| TRHU | Triton Container International |
| TRIN | Trinidad Railway |