| 1 | TTO | Air Transport & Transit Regional | Callsign: Transport Transit, | RM | AVCODES |
| 2 | TTOB | TALLEY TRUCKING CO INC | | | SCAC4 |
| 3 | TTOC | TRINITY TRANSPORTATION COMPANY INC | | | SCAC4 |
| 4 | TTOG | TT OCEAN LOGISTICS LLC | | | SCAC4 |
| 5 | TTOI | T-TRADER ONE LTD | | | SCAC4 |
| 6 | TTOL | TNT OLEX, INC | | | SCAC1 |
| 7 | TTOL | TST EXPEDITED SERVICES INC | | | SCAC4 |
| 8 | TTOR | TRANSPORTES TOROCO | | | SCAC4 |
| 9 | TTOS | TRIMAC TRANSPORTATION SERVICES (WES | | | SCAC4 |
| 10 | TTOU | TOTAL CONTAINERS PTY LTD | | AUS | BIC |
| 11 | TTOW | TAYLORS TOWING | | | SCAC4 |
| 12 | TTOX | Trailer Train Co. | added 10/1987; eliminated 1/1992 | | NAKINA |
| 13 | TTOX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 14 | TTOX | Trailer Train Co./TTX Co. (single platform TOFC cars with modified single axle trucks and rigid hitch, capable of carrying 1 trailer 40-48' long, up to 102"" wide with nose-mounted refrigeration unit; between lift-on/lift-off facilities only) | added 10/1987; 10/1991-7/2000 | | NAKINA |
| 15 | TTOX | Trailer Train Co. | added 10/87; eliminated 1/92 | | NRHS |
| 16 | TTOX | TTX Co. | added 1/92 | | NRHS |
| 17 | TTOX | TTX Co. (single platform TOFC cars with modified single axle trucks and rigid hitch, capable of carrying 1 trailer 40-48' long, up to 102" wide with nose-mounted refrigeration unit; between lift on/lift off facilities only) | 1/94-7/2000 | | NRHS |
| 18 | TTOX | TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 19 | TTOX | Trailer Train (TTX Corporation) | | | RSRV |
| 20 | TTOX | TTX COMPANY | | | SCAC4 |
| 21 | TTOZ | TOTEM OCEAN TRAILER EXPRESS, INC. | | | PWRC |
| 22 | TTOZ | Totem Ocean Trailer Express | | | RSRV |
| 23 | TTOZ | TOTEM OCEAN TRAILER EXPRESS, INC. | | | SCAC4 |
