| 1 | ARD | ATA Aerocondor Transportes Aéreos Lda. | IATA: 2B, Callsign: Aerocondor, IATA Prefix: 088, Suspended operation in May 2008. Designator 2B reinstated by IATA | P | AVCODES |
| 2 | ARD | Aerocondor Transportes Aereos Lda. | IATA: 8W, IATA designator changed from 2B | P | AVCODES |
| 3 | ARD | Aerocondor | IATA: 2B | | ICAO1 |
| 4 | ARD | Aerocondor | | PE | TRAFFIC |
| 5 | ARDA | ARD, AUBURN D | | | SCAC3 |
| 6 | ARDB | ARD B TRANSPORT INC | | | SCAC4 |
| 7 | ARDC | ADIRONDACK RAILWAY | | | PWRC |
| 8 | ARDC | ARMISTEAD TRUCKING INC | | | SCAC3 |
| 9 | ARDD | AMERICAN INTERMODAL TRANSPORT INC | | | SCAC4 |
| 10 | ARDE | A-RIDE | | | SCAC3 |
| 11 | ARDE | ARDELLA TRUCKING INC | | | SCAC4 |
| 12 | ARDE | Arriva Deutschland | | D | TRAFFIC |
| 13 | ARDG | ARDS TRUCKING COMPANY INCORPORATED | | | SCAC3 |
| 14 | ARDG | ARDS TRUCKING COMPANY INCORPORATED | | | SCAC4 |
| 15 | ARDH | ARDEN AIR FREIGHT INC | | | SCAC3 |
| 16 | ARDH | ARTECH REDUCTION TECHNOLOGIES | | | SCAC4 |
| 17 | ARDI | A & R DELIVERY SERVICE | | | SCAC3 |
| 18 | ARDJ | ARD TRUCKING | | | SCAC3 |
| 19 | ARDJ | AUTO TRANSPORTES SAHORA DE B C | | | SCAC4 |
| 20 | ARDK | ALLARDS | | | SCAC3 |
| 21 | ARDK | ARVOR INC | | | SCAC4 |
| 22 | ARDL | AMERICAN ROAD LINES INC | | | SCAC3 |
| 23 | ARDL | AMERICAN ROAD LINES INC | | | SCAC4 |
| 24 | ARDM | ALL-ROADS MOVING & STORAGE INC | | | SCAC3 |
| 25 | ARDM | ARCHER-DANIELS-MIDLAND COMPANY | | | SCAC4 |
| 26 | ARDO | AREA DELIVERY SERVICE | | | SCAC3 |
| 27 | ARDO | ARO | | | SCAC4 |
| 28 | ARDP | Union Pacific R.R. Co. | added 4/1997; 7/2000-7/2005 | | NAKINA |
| 29 | ARDP | Missouri Pacific System | 1/1994; eliminated 4/1997 | | NAKINA |
| 30 | ARDP | Doniphan, Kensett & Searcy Ry. | eliminated 1/1979; 1/1980 | | NAKINA |
| 31 | ARDP | Missouri Pacific R.R. Co. | 1/1975 | | NAKINA |
| 32 | ARDP | Missouri Pacific R.R. Co. | Jan-75 | | NRHS |
| 33 | ARDP | Doniphan, Kensett & Searcy Ry. | eliminated 1/79; 1/80 | | NRHS |
| 34 | ARDP | Missouri Pacific System | 1/94; eliminated 4/97 | | NRHS |
| 35 | ARDP | Union Pacific R.R. Co. | added 4/97; 7/2000 | | NRHS |
| 36 | ARDP | UP [MISSOURI PACIFIC RAILROAD (LEASED THROUGH ART FROM E.I. DUPONT)] | | | PWRC |
| 37 | ARDP | Missouri Pacific Railroad (Union Pacific Railroad) | | | RSRV |
| 38 | ARDQ | ARDREY, FRED A | | | SCAC3 |
| 39 | ARDQ | ARD LOGISTICS OF ALABAMA LLC | | | SCAC4 |
| 40 | ARDR | ARDMORE FARMS INC | | | SCAC3 |
| 41 | ARDS | ARDIS, H TRUCKING COMPANY | | | SCAC3 |
| 42 | ARDT | ARCADIA TRANSPORTATION CO | | | SCAC3 |
| 43 | ARDT | ALLRED TRANSPORT INC | | | SCAC4 |
| 44 | ARDU | CARU CONTAINERS BV | | NL | BIC |
| 45 | ARDU | CATU CONTAINERS S.A. | | | PWRC |
| 46 | ARDU | CARU Containers | | | RSRV |
| 47 | ARDU | CATU CONTAINERS S.A. | | | SCAC3 |
| 48 | ARDU | CONTAINER ASSOCIATION ROTTERDAM BV | | | SCAC4 |
| 49 | ARDV | ARMSTRONG, DAVE TRUCKING | | | SCAC3 |
| 50 | ARDV | ARREDONDO VILLARREAL, LEONEL | | | SCAC4 |
| 51 | ARDW | ARROW DRIVEAWAY INC | | | SCAC3 |
| 52 | ARDW | AFT EXPRESS TRANSPORT | | | SCAC4 |
| 53 | ARDX | American Refrigerator Transit Co. | added 4/1953; 7/1954-10/1957; eliminated 4/1961 | | NAKINA |
| 54 | ARDX | American Reduction Co. of Pittsburgh | 7/1935-4/1938 | | NAKINA |
| 55 | ARDX | American Reduction Co. of Pittsburgh | Apr-38 | | NRHS |
| 56 | ARDX | American Refrigerator Transit Co. | 10/57; eliminated 4/61 | | NRHS |
| 57 | ARDX | *AMERICAN REDUCTION CO. OF PITTSBURGH | | | PWRC |
| 58 | ARDX | *AMERICAN REFRIGERATOR TRANSIT CO. (ELIMINATED 4/1961) | | | PWRC |
