| 6501 | ROOV | ROBERTSONS OVERLAND EXPRESS | SCAC3 | ||
| 6502 | ROP | Royal Oman Police | ICAO1 | ||
| 6503 | ROP | RAIL OPERATIONS SRL | RO | VKM | |
| 6504 | ROPA | RONSON TRANSPORTATION INC | SCAC3 | ||
| 6505 | ROPAG | ROP Roth AG | DE | VKM | |
| 6506 | ROPAN | EUROPAN PROD SA | RO | VKM | |
| 6507 | ROPC | ROGERS PETRO-CHEM CO | SCAC3 | ||
| 6508 | ROPE | ROMERO, PAT FEEDS AND SUPPLY | SCAC3 | ||
| 6509 | ROPE | ROTATION POWER & EQUIPMENT | SCAC4 | ||
| 6510 | ROPG | ROYAL PROCESSING CO INC | SCAC3 | ||
| 6511 | ROPN | ROSE TRANSPORTATION INC | SCAC3 | ||
| 6512 | ROPR | ROSE TRANSPORTATION INC | SCAC3 | ||
| 6513 | ROPS | ROCAROL PARCEL SYSTEM | SCAC3 | ||
| 6514 | ROPT | ROPPE TRANSPORTATION CORPORATION | SCAC3 | ||
| 6515 | ROPX | Rail Operators, Inc. | added 7/1993; 1/1994; eliminated 4/1997; 7/2000 (not listed) | NAKINA | |
| 6516 | ROPX | Rail Operators, Inc. | added 7/93; 1/94; eliminated 4/97; 7/2000 | NRHS | |
| 6517 | ROPX | RAIL OPERATORS, INC. | PWRC | ||
| 6518 | ROPX | Rail Operators | RSRV | ||
| 6519 | ROQS | ROSES TRANSPORT INC | SCAC4 | ||
| 6520 | ROQT | ROSS, R L EQUIPMENT | SCAC3 | ||
| 6521 | ROR | Roraima Airways | ICAO1 | ||
| 6522 | ROR | Rockton & Rion Ry. | 1/1975-1/1980 | NAKINA | |
| 6523 | ROR | Rockton & Rion Ry. | 1/75-1/80 | NRHS | |
| 6524 | ROR | FORMERLY ROCKTON & RION RAILROAD | PWRC | ||
| 6525 | ROR | ROCKTON & RION RAILWAY | SCAC4 | ||
| 6526 | RORA | ROGER A LEASING LTD (DIV OF AIPA) | SCAC3 | ||
| 6527 | RORB | ROMERO ORTEGA, RUBEN | SCAC4 | ||
| 6528 | RORF | ROARING FORK FOUNDERS | SCAC3 | ||
| 6529 | RORF | ROMERO ROBLES, FAUSTO | SCAC4 | ||
| 6530 | RORG | ROANES RIGGING & TRANSFER CO INC | SCAC3 | ||
| 6531 | RORI | ROTRA INC | SCAC3 | ||
| 6532 | RORI | ROTRA LLC | SCAC4 | ||
| 6533 | RORL | ROMAN, R TRUCK LEASING INC | SCAC3 | ||
| 6534 | RORL | ROMAN, R TRUCK LEASING INC | SCAC4 | ||
| 6535 | RORM | ROADRUNNER MOTOR LINES INC | SCAC3 | ||
| 6536 | RORN | ROADRUNNER EXPRESS SERVICE | SCAC3 | ||
| 6537 | RORO | RODCO TRANSPORTATION | SCAC3 | ||
| 6538 | RORP | ROAD RUNNER EXPRESS | SCAC3 | ||
| 6539 | RORR | ROPER TRUCKING SERVICE | SCAC3 | ||
| 6540 | RORT | ROAD RAIL TRANSPORT LTD | SCAC3 | ||
| 6541 | RORT | RO TRANSPORT | SCAC4 | ||
| 6542 | RORU | Road Runner | Fleetname for some S.M.Coaches operations | GB | TRAFFIC |
| 6543 | RORX | Radio Oil Refineries, Ltd. | 7/1937 (not listed); 4/1938-1/1952; eliminated 4/1953 | NAKINA | |
| 6544 | RORX | Radio Oil Refineries, Ltd. | 4/38-1/52 | NRHS | |
| 6545 | RORX | *RADIO OIL REFINERIES, LTD. | PWRC | ||
| 6546 | RORX | +RED OAK RAIL TRANSPORT, LLC | PWRC | ||
| 6547 | RORY | ROUTH, RAY & SONS INC | SCAC3 | ||
| 6548 | RORZ | ROBINSON RUN | PWRC | ||
| 6549 | ROS | Rossair Europe | ICAO1 | ||
| 6550 | ROSA | RENOWN CO SA, PANAMA REP OF PANAMA | SCAC3 | ||
| 6551 | ROSA | ROSALYN TANKER CORPORATION | SCAC4 | ||
| 6552 | ROSB | ROSENBAUM CARREON, RENE | SCAC4 | ||
| 6553 | ROSC | RODINO SHIPPING COMPANY LIMITED | SCAC4 | ||
| 6554 | ROSD | ROSS TRANSPORT CO INC | SCAC3 | ||
| 6555 | ROSE | ROSENBERGER ENTERPRISES INC | SCAC3 | ||
| 6556 | ROSE | ROSE INTERNATIONAL INC | SCAC4 | ||
| 6557 | ROSG | ROAD SERVICE GARAGE | SCAC3 | ||
| 6558 | ROSI | ROSEVILLE MOTOR EXPRESS, INC | SCAC3 | ||
| 6559 | ROSI | ROSEVILLE MOTOR EXPRESS INC | SCAC4 | ||
| 6560 | ROSL | ROSEVELT, JAMES L | SCAC3 | ||
| 6561 | ROSL | ROSE LOGISTICS INC | SCAC4 | ||
| 6562 | ROSM | ROSE, WILLIAM GARY | SCAC3 | ||
| 6563 | ROSM | RESORTES K-L DE MEXICO SA DE CV | SCAC4 | ||
| 6564 | ROSO | ROSALIUS, CURTIS H | SCAC3 | ||
| 6565 | ROSO | ROSARIO E N E | SCAC4 | ||
| 6566 | ROSP | ROSEMAN, E, COMPANY | SCAC3 | ||
| 6567 | ROSQ | ROSAS TRANSPORTATION & EQUIPMENT LE | SCAC3 | ||
| 6568 | ROSQ | ROSSER TRUCKING | SCAC4 | ||
| 6569 | ROSR | ROSS, ROY TRUCKING COMPANY | SCAC3 | ||
| 6570 | ROSS | ROSS TRANSPORTATION | SCAC3 | ||
| 6571 | ROSS | RANGER OILFIELD SERVICES | SCAC4 | ||
| 6572 | ROST | ROBLIN STEEL | PWRC | ||
| 6573 | ROSU | ROOS SPEDITION GMBH | SCAC4 | ||
| 6574 | ROSV | ROSES TRANSPORTATION | SCAC4 | ||
| 6575 | ROSX | Ross and Company, Inc. | 7/1935 | NAKINA | |
| 6576 | ROSY | ROSE-WAY INC | SCAC3 | ||
| 6577 | ROSY | ROBINSON OIL SUPPLY & TRANSPORT INC | SCAC4 | ||
| 6578 | ROSZ | ROSS TRUCKING LLC | SCAC4 | ||
| 6579 | ROT | Tarom | IATA: RO | ICAO1 | |
| 6580 | ROT | RAIL OR TRAIL CORP. | PWRC | ||
| 6581 | ROT | Rotterdamse Elektrische Tram | Real: RET, City: Rotterdam | NL | TRAFFIC |
| 6582 | ROTA | ROOT, A L, TRANSPORTATION, INC | SCAC3 | ||
| 6583 | ROTB | ROSSI, THEODORE TRUCKING CO, INC | SCAC3 | ||
| 6584 | ROTC | ROSE TRUCKING CORP | SCAC4 | ||
| 6585 | ROTD | ROTENBERGER, DAVID M | SCAC3 | ||
| 6586 | ROTD | ROOT, DALE S TRUCKING | SCAC4 | ||
| 6587 | ROTE | ROBERTS TRADING CORP | SCAC3 | ||
| 6588 | ROTE | ROTEC INTERNATIONAL | SCAC4 | ||
| 6589 | ROTEDD | Die Rote Doppeldecker GmbH | D | TRAFFIC | |
| 6590 | ROTER | TERMICA SA | RO | VKM | |
| 6591 | ROTF | ROAD/TRAIN | SCAC3 | ||
| 6592 | ROTH | ROTHROCK, J L, INC | SCAC3 | ||
| 6593 | ROTH | ROTHROCK, J L INC | SCAC4 | ||
| 6594 | ROTHC | Rotherham Corporation Transport | GB | TRAFFIC | |
| 6595 | ROTI | ROGERS TRUCKING INC | SCAC3 | ||
| 6596 | ROTI | ROGERS TRUCKING INC | SCAC4 | ||
| 6597 | ROTJ | R ONE TWO (R12) PORK LTD | SCAC4 | ||
| 6598 | ROTK | ROSS TRUCKING COMPANY | SCAC3 | ||
| 6599 | ROTK | ROBERTS TRUCKING LLC | SCAC4 | ||
| 6600 | ROTL | ROSS TRUCK LINES INC | SCAC3 |