| Abbreviation | Definition |
|---|---|
| TRRU | Transport Resources |
| TRRY | Trillium Railway |
| TRS | Trainz Railroad Simulator |
| TRSU | Transconex |
| TRSU | Transconex Incorporated |
| TRSX | Transrail Systems (GE Rail Services) |
| TRT | Third Rail Therapy |
| TRTX | W. J. Kirberger |
| TRTX | W. J. Kirberger Trustee |
| TRUX | Midwest Bottle Gas |
| TRUX | Midwest Bottle Gas Company |
| TRVU | Triton Container International |
| TRYX | Tri-County Cooperative Association |
| TRZU | Transamerican Container Leasing |
| TRZU | Transamerican Container Leasing Company |
| TRZZ | TAL International |
| TRZZ | Transamerica Leasing Incorporated |
| TS | Tidewater Southern Railway |
| TSBY | Tuscola and Saginaw Bay Railway |
| TSBY | Tuscola and Saginaw Bay Railway Company |