| Abbreviation | Definition |
|---|---|
| TOPS | Total Operations Processing System |
| TOR | RaiLink Canada Limited |
| TOR | RailLink Canada Limited (Genesee & Wyoming) |
| TORU | Torm Lines |
| TORZ | Torco Inc |
| TORZ | Torco, Inc. |
| TOSN | Train routing Toledo, Ohio, to Saginaw, Michigan |
| TOTU | Tiphook Container |
| TOTU | Tiphook Container Rental Company Limited |
| TOTX | Cotco |
| TOTX | Cotco Incorporated |
| TOV | Tooele Valley Railway |
| TP | Texas and Pacific Railway (Union Pacific Railroad) |
| TP | Union Pacific Railroad Company |
| TPBX | General American Transportation Corporation (GATX) |
| TPCX | The Purdy Co. (Trademark Plastics Corp) |
| TPCZ | Tiphook Container Rental Company Limited |
| TPCZ | Tiphook Container Rental Limited |
| TPEX | General Electric Railcar Services Corporation |
| TPFX | General Electric Railcar Services Corporation |