| 1 | WTOC | WILMINGTON TRANSPORTATION CENTER | | | SCAC4 |
| 2 | WTOF | WEST TEXAS OILFIELD TRUCKING COMPAN | | | SCAC4 |
| 3 | WTOH | Western Ohio R.R. Co. | 1/1980; eliminated 4/1981 | | NAKINA |
| 4 | WTOH | Western Ohio R.R. Co. | 1/80; eliminated 4/81 | | NRHS |
| 5 | WTOH | WESTERN OHIO RAILROAD | | | PWRC |
| 6 | WTOH | Western Ohio Railroad | | | RSRV |
| 7 | WTOI | WATSON INC | | | SCAC4 |
| 8 | WTOJ | WELESKI TRANSFER OF JOHNSTOWN | | | SCAC4 |
| 9 | WTOL | WESTERN TRUCKING 1 LLC | | | SCAC4 |
| 10 | WTOO | WILSONS TRANSPORTATION INC | | | SCAC4 |
| 11 | WTOP | WTO EXPRESS CORP | | | SCAC4 |
| 12 | WTOS | WESTERN AUTO SUPPLY COMPANY | | | SCAC1 |
