AMTK
| Amtrak | 9 |
BCT
| BCT | 1 |
BO
| Baltimore & Ohio | 1 |
CG
| Central Of Georgia | 1 |
CR
| Conrail | 1 |
DLCR
| DLCR | 2 |
HARS
| HARS | 1 |
HVRX
| Heber Valley Historic Railroad | 1 |
HZGX
| Herzog Contracting Corporation | 1 |
LMIX
| Loram Maintenance of Way Inc. | 1 |
MEC
| Maine Central | 1 |
NJT
| New Jersey Transit | 12 |
NS
| Norfolk Southern | 12 |
RCC
| RCC | 2 |
RDG
| Reading Railroad | 1 |
SLRS
| SMS Rail Service Incorporated | 2 |
SPAX
| Southeastern Pennsylvania Transportation (SEPTA) | 5 |
SRNJ
| Southern Railroad Company of New Jersey | 1 |
UP
| Union Pacific Railroad Company | 1 |
UTAH
| Utah Railway | 1 |