| 1 | TTG | Transtel SA | Callsign: Transtel, Ceased operations. | TG | AVCODES |
| 2 | TTGB | TSD TRANSPORTATION, LP (DIVISION IN | | | SCAC4 |
| 3 | TTGC | TECATE TRUCKING LLC | | | SCAC4 |
| 4 | TTGD | TRANSPORT G D M INC | | | SCAC4 |
| 5 | TTGE | TRIO TRUCKING INC (INTERMODAL DIVIS | | | SCAC4 |
| 6 | TTGG | TRANSPORTES GALLEGO | | | SCAC4 |
| 7 | TTGGE | Tyczka Gase GmbH | | DE | VKM |
| 8 | TTGI | TRANSPORTATION GROUP INC | | | SCAC4 |
| 9 | TTGJ | TRUMBLE TRUCKING LLC | | | SCAC4 |
| 10 | TTGL | TRANSPORTES GALA | | | SCAC4 |
| 11 | TTGM | TRANSPORTES GOMEZ | | | SCAC4 |
| 12 | TTGO | TRANS CONTAINER | | | SCAC1 |
| 13 | TTGO | TRIO TRUCKING INC | | | SCAC4 |
| 14 | TTGP | TOPS TRUCKING, INC | | | SCAC1 |
| 15 | TTGP | TOPS TRUCKING INC | | | SCAC4 |
| 16 | TTGU | CHEMOVIL LTD | | | SCAC4 |
| 17 | TTGX | Trailer Train Co. | 4/1970-1/1975; added 1/1977; 1/1980; eliminated 1/1992 | | NAKINA |
| 18 | TTGX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 19 | TTGX | Trailer Train Co. | 4/1970 | | NAKINA |
| 20 | TTGX | Trailer Train Co. (no definition) | 1/1975 | | NAKINA |
| 21 | TTGX | Trailer Train Co. | 4/1970; added 1/1977 | | NAKINA |
| 22 | TTGX | Trailer Train Co./TTX Co. (flat cars equipped with fully enclosed bi-level auto racks furnished by participant railroads) | 1/1980-1/1994 | | NAKINA |
| 23 | TTGX | TTX Co. (flat cars equipped with fully enclosed bi-level auto racks furnished by participant railroads, equipped with end of car cush.) | 7/2000 | | NAKINA |
| 24 | TTGX | Trailer Train Co. | Apr-70 | | NRHS |
| 25 | TTGX | Trailer Train Co. (no definition) | Jan-75 | | NRHS |
| 26 | TTGX | Trailer Train Co. | 4/70; added 1/77 | | NRHS |
| 27 | TTGX | Trailer Train Co. (flat cars equipped with fully enclosed bi-level auto racks furnished by participant railroads) | 1/80; eliminated 1/92 | | NRHS |
| 28 | TTGX | TTX Co. (flat cars equipped with fully enclosed bi-level auto racks furnished by participant railroads) | added 1/92; 1/94 | | NRHS |
| 29 | TTGX | TTX Co. (flat cars equipped with fully enclosed bi-level auto racks furnished by participant railroads, equipped with end of car cush.) | Jul-00 | | NRHS |
| 30 | TTGX | TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 31 | TTGX | Trailer Train (TTX Corporation) | | | RSRV |
| 32 | TTGX | TTX COMPANY | | | SCAC4 |
| 33 | TTGY | TUFF TRANSPORT INC | | | SCAC4 |