| 1 | RTA | Regional Transportation Authority | 1/1980 | | NAKINA |
| 2 | RTA | Regional Transportation Authority | Jan-80 | | NRHS |
| 3 | RTA | REGIONAL TRANSPORTATION AUTHORITY (NOT AN OPERATING RAILROAD) | | | PWRC |
| 4 | RTA | Regional Transportation Authority, Chicago | | USA | TRAFFIC |
| 5 | RTAB | R & K TRUCKING | | | SCAC4 |
| 6 | RTAC | ROWE | | | SCAC4 |
| 7 | RTACA | Riverside Transit Agency | Real: RTA, City: Riverside | US-CA | TRAFFIC |
| 8 | RTAD | RITE AID TRANSPORT INC | | | SCAC4 |
| 9 | RTAE | RILO TRUCKING LLC | | | SCAC4 |
| 10 | RTAF | Régie des transports de l'Aisne | | F | TRAFFIC |
| 11 | RTAG | RISTVEBT TRUCKING & GRAIN SERVICE | | | SCAC3 |
| 12 | RTAG | RISTVEDT TRUCKING AND GRAIN SERVICE | | | SCAC4 |
| 13 | RTAH | RTA INTERNATIONAL INC | | | SCAC3 |
| 14 | RTAJ | RARA TRANSPORT | | | SCAC4 |
| 15 | RTAK | ROACH TRUCKING | | | SCAC4 |
| 16 | RTAL | ROSEDALE TRANSPORT LTD | | | SCAC3 |
| 17 | RTAL | ROSEDALE TRANSPORT LTD | | | SCAC4 |
| 18 | RTAM | RICHARDS TRUCKING AND MESSENGER SER | | | SCAC3 |
| 19 | RTAN | ROBBINS TRANSPORT INC | | | SCAC3 |
| 20 | RTAO | ROSE TRANSPORTATION INC | | | SCAC3 |
| 21 | RTAO | ROBERTS, T A OIL CO INC | | | SCAC4 |
| 22 | RTAP | RAYS TRANSPORTATION INC | | | SCAC3 |
| 23 | RTAP | RAM TRANSPORT INC | | | SCAC4 |
| 24 | RTAR | ROTARY TECHNOLOGY INC | | | SCAC3 |
| 25 | RTAS | RUGGED TRANSPORT | | | SCAC4 |
| 26 | RTAT | REGIONAL TRANSIT AUTHORITY/ART INC, | | | SCAC3 |
| 27 | RTAU | ROBOTANKS | | UA | BIC |
| 28 | RTAW | ROSEWOODS TRANSPORTATION INC | | | SCAC4 |
| 29 | RTAX | RENFE TALGO OF AMERICA, INC. | | | PWRC |
| 30 | RTAX | RIO TINTO ALCAN | | | SCAC4 |
| 31 | RTAY | RITEWAY TRANSPORTS LLC | | | SCAC4 |
