| Abbreviation | Definition |
|---|---|
| TTCX | Trailer Train (TTX Corporation) |
| TTCX | TTX Company |
| TTDX | Trailer Train (TTX Corporation) |
| TTDX | TTX Company |
| TTER | Tomiko Tilden & Eastern Railway |
| TTEX | Trailer Train (TTX Corporation) |
| TTEX | TTX Company |
| TTFX | Trailer Train (TTX Corporation) |
| TTFX | TTX Company |
| TTGX | Trailer Train (TTX Corporation) |
| TTGX | TTX Company |
| TTHX | Trailer Train (TTX Corporation) |
| TTHX | TTX Company |
| TTIS | Transkentucky Transportation Railroad |
| TTIS | Transkentucky Transportation Railroad Incorporated |
| TTIU | Thailand Tantalum Industry Corporation Limited |
| TTIX | Trailer Train (TTX Corporation) |
| TTIZ | Tandem Transport |
| TTIZ | Tandem Transport Incorporated |
| TTJX | Trailer Train (TTX Corporation) |