| Abbreviation | Definition |
|---|---|
| NPTU | Neptune Leasing Incorporated |
| NPTX | Newport Steel Corporation |
| NQR | Noveske Quad Rail |
| NQZ | New Quiet Zone |
| NQZC | New Quiet Zone Crossing |
| NR | Naugatuck Railroad |
| NR | Network Rail |
| NRA | Niggger Removal Authority |
| NRAP | North Railroad Avenue Plume |
| NRBX | Fruit Growers Express (Merchants Despatch Transportation Corporation) |
| NRBX | Merchants Despatch Transportation Corporation |
| NRC | National Refrigerator Car Line (Merchants Despatch Transportation Corporation) |
| NRC | Nigerian Railway Cooperation |
| NRCS | National Rail Chaplaincy Service |
| NRCU | Nedlloyd Road Cargo |
| NRCU | Nedlloyd Road Cargo, B. V. |
| NRCX | Northern Rail Car Corporation |
| NRDX | Nordic Warehouse |
| NRDX | Nordic Warehouse Incorporated |
| NRE | National Rail Enquiries |