| 9501 | RTTX | Trailer Train Co. | eliminated 7/1984 | | NAKINA |
| 9502 | RTTX | Trailer Train Co. (standard deck, 3-hitch flat cars with non-collapsible hitches at the ends of the car and a collapsible hitch at the centre of the car, capable of carrying 3-28' trailers with kingpin spacing of 36"" or less, or any two trailers with 36"" kingpin spacing, whose overall combined length does not exceed 90' (i.e. 2-45', 1-42' & 1-48', 1-40' & 1-48', etc.), between lift-on/lift-off facilities only) | 7/1985 | | NAKINA |
| 9503 | RTTX | Trailer Train Co./TTX Co. (89' and 360' TOFC cars. 89' cars (6 digit car numbers other than 165000 series) are standard deck, 3-hitch flatcars with non-collapsable hitches at the ends of the car and a collapsable hitch at the centre of the car, capable of carrying 3-28' trailers with kingpin spacing of 36"" or less, or any two trailers with 36"" kingpin spacing, whose overall combined length does not exceed 90' — i.e., 2-45', 1-42' & 1-48', 1-40' & 1-48', etc. — between lift-on/lift-off facilities only. 360 | added 7/1986; 10/1991-1/1992 | | NAKINA |
| 9504 | RTTX | TTX Co. (89' and 178' TOFC Flat cars. 89' cars (6 digit car numbers other than 165000 series) are standard deck, 3-hitch flatcars with non-collapsable hitches at the ends of the car and a collapsable hitch at the centre of the car, capable of carrying 3-28' trailers with kingpin spacing of 36"" or less, or any two trailers with 36"" kingpin spacing, whose overall combined length does not exceed 90' — i.e., 2-45', 1-42' & 1-48', 1-40' & 1-48', etc. — between lift-on/lift-off facilities only. 178' cars (6 dig | 1/1994-7/2000 | | NAKINA |
| 9505 | RTTX | Trailer Train Co. | 4/61-7/65 | | NRHS |
| 9506 | RTTX | Trailer Train Co. (FA flat cars equipped with tri-level automobile carrying superstructures furnished by member railroads. Cars are not equipped with hitches and bridge plates) | 10/66-10/68 | | NRHS |
| 9507 | RTTX | Trailer Train Co. | Apr-70 | | NRHS |
| 9508 | RTTX | Trailer Train Co. (flat cars, equipped with fixed tri-level auto racks furnished by participant railroads) | 1/75-1/80 | | NRHS |
| 9509 | RTTX | Trailer Train Co. | eliminated 7/84 | | NRHS |
| 9510 | RTTX | Trailer Train Co. | added 7/86; eliminated 1/92 | | NRHS |
| 9511 | RTTX | TTX Co. | added 1/92 | | NRHS |
| 9512 | RTTX | TTX Co. (89' and 178' TOFC Flat cars. 89' cars (6 digit car numbers other than 165000 series) are standard deck, 3-hitch flatcars with non-collapsable hitches at the ends of the car and a collapsable hitch at the centre of the car, capable of carrying 3 28' trailers with kingpin spacing of 36" or less, or any two trailers with 36" kingpin spacing, whose overall combined length does not exceed 90' -- i.e., 2-45', 1-42' & 1-48', 1-40' & 1-48', etc. -- between lift on/lift off facilities only. 178' cars (6 dig | 1/94-7/2000 | | NRHS |
| 9513 | RTTX | *RAPID TRANSIT TANK CAR LINE | | | PWRC |
| 9514 | RTTX | +TTX COMPANY | | | PWRC |
| 9515 | RTTX | TTX Corporation | | | RSRV |
| 9516 | RTTX | TTX COMPANY | | | SCAC4 |
| 9517 | RTTY | ROCKY TOP TRUCKING | | | SCAC4 |
| 9518 | RTTZ | UP [(REAZ) RETIRED 04-06-93 ATP (ACI 2384)] | | | PWRC |
| 9519 | RTTZ | Union Pacific Railroad | | | RSRV |
| 9520 | RTU | Aerotucan, S.A. de C.V. | Callsign: Aerotucan, | MEX | AVCODES |
| 9521 | RTU | Aerotucan | | | ICAO1 |
| 9522 | RTUC | R & R TRUCKING | | | SCAC3 |
| 9523 | RTUC | R & T TRUCK INC | | | SCAC4 |
| 9524 | RTUD | RENTALS UNLIMITED INC | | | SCAC3 |
| 9525 | RTUE | RODAN TRANSPORT USA LTD | | | SCAC4 |
| 9526 | RTUG | RATH TRUCKING, INC | | | SCAC3 |
| 9527 | RTUG | RATH TRUCKING INC | | | SCAC4 |
| 9528 | RTUI | RUSSELL TRUCKING INC | | | SCAC3 |
| 9529 | RTUL | Rail Technologie und Logistics GmbH | Magdeburg | D | privat-bahn.de |
| 9530 | RTUL | ROLLEN TRUCK LINES INC | | | SCAC3 |
| 9531 | RTUL | Rail Rechnology & Logistics GmbH | | DE | VKM |
| 9532 | RTUN | RTS TRUCKING CO | | | SCAC3 |
| 9533 | RTUQ | RTL TRUCKING LTD | | | SCAC4 |
| 9534 | RTUS | RATLIFFS TRUCKING SERVICE INC | | | SCAC3 |
| 9535 | RTV | Nortavia | Callsign: Tic-Tac, | P | AVCODES |
| 9536 | RTV | Nortavia | | | ICAO1 |
| 9537 | RTVA | R & T TRUCKING INC | | | SCAC3 |
| 9538 | RTVC | ROAD TRIP TOURS | | | SCAC3 |
| 9539 | RTVE | R T EXPRESS | | | SCAC4 |
| 9540 | RTVI | R T SERVICES INC | | | SCAC3 |
| 9541 | RTVL | ROBYNS TRUCKING SEVICES LTD | | | SCAC3 |
| 9542 | RTVR | RETRIEVER TRANSPORTATION INC | | | SCAC4 |
| 9543 | RTVS | RELIABLE TRANSPORT SERVICES | | | SCAC4 |
| 9544 | RTVU | DAILY RENTAL SERVICES BV | | NL | BIC |
| 9545 | RTW | Rail To Water | | USA | TRAFFIC |
| 9546 | RTWA | RITEWAY TRANSFER | | | SCAC3 |
| 9547 | RTWD | ROUND THE WORLD (USA) CORP. | | | SCAC3 |
| 9548 | RTWD | R TWO (R2) LOGISTICS INC (LTL DIVIS | | | SCAC4 |
| 9549 | RTWE | RTW ENTERPRISES | | | SCAC3 |
| 9550 | RTWE | RTW ENTERPRISES INC | | | SCAC4 |
| 9551 | RTWF | READS TOWING | | | SCAC3 |
| 9552 | RTWH | REDWAY TRUCK & WAREHOUSE COMPANY | | | SCAC3 |
| 9553 | RTWH | RAIL TRANSFER AND WAREHOUSING INC | | | SCAC4 |
| 9554 | RTWK | ROSS TOWING AND TRANSPORTATION SERV | | | SCAC4 |
| 9555 | RTWP | RITE-WAY TRANSPORTATION INC | | | SCAC3 |
| 9556 | RTWQ | RITEWAY MOTOR FRT CO | | | SCAC3 |
| 9557 | RTWQ | RITEWAY MOTOR FRT CO | | | SCAC4 |
| 9558 | RTWR | ROAD-RUNNER TOWING & RECOVERY | | | SCAC3 |
| 9559 | RTWR | RONS TOWING AND RECOVERY INC | | | SCAC4 |
| 9560 | RTWT | RITE WAY TRANSPORTATION INC | | | SCAC3 |
| 9561 | RTWT | RITE WAY TRANSPORTATION INC | | | SCAC4 |
| 9562 | RTWY | RITE-WAY TRANSPORT COMPANY INC | | | SCAC3 |
| 9563 | RTWY | RITE-WAY TRANSPORT COMPANY INC | | | SCAC4 |
| 9564 | RTX | Railtraxx BVBA | | BE | VKM |
| 9565 | RTXA | RELIABLE TRANSPORTATION | | | SCAC4 |
| 9566 | RTXC | R TRANSPORTATION LLC | | | SCAC4 |
| 9567 | RTXD | RENEW TRANSPORTATION LLC | | | SCAC4 |
| 9568 | RTXE | RELIANT TRANSPORT INC | | | SCAC4 |
| 9569 | RTXG | RTX LOGISTICS | | | SCAC4 |
| 9570 | RTXH | ROLYNNS TRANSPORTATION INC | | | SCAC4 |
| 9571 | RTXI | RAYTRUX INC | | | SCAC3 |
| 9572 | RTXI | ROMERO TRUCK EXPORTATION | | | SCAC4 |
| 9573 | RTXJ | REDWOOD TRANSPORT INC | | | SCAC4 |
| 9574 | RTXK | ROUNDTREE TRANSPORT LLC | | | SCAC4 |
| 9575 | RTXL | READY TAXI AND LIMOUSINE INC | | | SCAC3 |
| 9576 | RTXM | ROE TRANSPORT INC | | | SCAC4 |
| 9577 | RTXO | ROCKSTAR TRANSPORTATION INC | | | SCAC4 |
| 9578 | RTXP | RAPID TRANSFER XPRESS | | | SCAC4 |
| 9579 | RTXS | ROM TRANS EXPRESS INC | | | SCAC4 |
| 9580 | RTXV | ROORDA TRANSPORT CO | | | SCAC4 |
| 9581 | RTXW | RUETHER TRANSPORTATION INC | | | SCAC4 |
| 9582 | RTXY | RITTER TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 9583 | RTY | Aims Community College | Callsign: Aims College, | USA | AVCODES |
| 9584 | RTYE | ROAD TRAIN EXPRESS INC | | | SCAC4 |
| 9585 | RTYI | ROBERTS, TOMMY TRUCKING INC | | | SCAC4 |
| 9586 | RTYS | RASMUSON, TYSON | | | SCAC4 |
| 9587 | RTYT | REYNA TRUCKING INC | | | SCAC4 |
| 9588 | RTZ | Regional Air Services | Callsign: Aerotuzla, | RO | AVCODES |
| 9589 | RTZA | RETZLAFF, BRIAN TRUCKING | | | SCAC4 |
| 9590 | RTZB | ROTZ, BRUCE | | | SCAC4 |
| 9591 | RTZC | R T Z TRUCKING COMPANY LLC | | | SCAC4 |
| 9592 | RTZF | RETZLAFF, ARTHUR | | | SCAC3 |
| 9593 | RTZF | RATZLAFF TRANSPORT | | | SCAC4 |
| 9594 | RTZG | RED TAZZ EXPRESS BROKERAGE AND LOGI | | | SCAC4 |
| 9595 | RTZK | RADDATZ, KEN TRUCKING | | | SCAC3 |
| 9596 | RTZL | REITZ OIL COMPANY | | | SCAC4 |
| 9597 | RTZN | RH TWO ZERO (RH2O) NORTH AMERICA | | | SCAC4 |
| 9598 | RTZO | RITTZO TRUCKING | | | SCAC3 |
| 9599 | RTZP | RITZ-TRANS CORPORATION OF PENNSYLVA | | | SCAC4 |
| 9600 | RTZS | RENTZ FARM SUPPLY | | | SCAC3 |
