| Abbreviation | Definition |
|---|---|
| AMRX | American Refining (Amerimex Rail) |
| AMRX | Consolidated Oil and Transportation Company Incorporated |
| AMRZ | American Chassis Leasing |
| AMSX | AllTrans Management Services Corporation |
| AMT | Agence métropolitaine de transport Montréal |
| AMTK | Amtrak (National Railroad Passenger Corporation) |
| AMTK | National Railroad Passenger Corporation |
| AMTZ | Amtrak |
| AMTZ | Amtrak (National Railroad Passenger Corporation) |
| AMWX | Amway Corporation |
| AMXU | Americas Marine Express |
| AMXU | Americas Marine Express Incorporated |
| AMXZ | Americas Marine Express |
| AMXZ | Americas Marine Express Incorporated |
| AMZU | Amphibious Container Leasing Limited |
| AN | Apalachicola Northern Railroad |
| AN | Apalachicola Northern Railroad (AN Railway) |
| ANAU | Alliance Navigation Line |
| ANAU | Alliance Navigation Line Incorporated |
| ANAX | General Electric Railcar Services Corporation |