| Abbreviation | Definition |
|---|---|
| CRR | Clinchfield Railroad (CSX Transportation) |
| CRR | CSX Transportation Incorporated |
| CRRR | Copper Range Refrigerator |
| CRRT | Commuter Rail Real Time |
| CRRU | Crimson Shipping |
| CRRX | Cañon City and Royal Gorge Railroad |
| CRS | Coast Rail Services |
| CRSD | Commuter Railroad System Division |
| CRSX | Cost Rail Service |
| CRTT | Centre for Rail Training and Technology |
| CRTZ | Conrail (Norfolk Southern) |
| CRTZ | Consolidated Rail Corporation |
| CRUMMIE | Vulgarism used in reference to railroad caboose, van, waycar: |
| CRXU | Cronos Containers |
| CRXU | Cronos Containers ( U. K.) |
| CRYX | Cryo-Trans |
| CRYX | Cryo-Trans Incorporated |
| CRZ | Conrail (Norfolk Southern) |
| CRZ | Consolidated Rail Corporation |
| CS | Burlington Northern and Santa Fe Railway Company |