AMTK
| Amtrak | 6 |
ATSF
| Atchison Topeka & Santa Fe | 6 |
BM
| Boston & Maine | 4 |
BN
| Burlington Northern | 1 |
BNSF
| BNSF Railway | 1 |
BO
| Baltimore & Ohio | 1 |
CR
| Conrail | 9 |
CSCV
| CSCV | 2 |
CSX
| CSX Railroad | 5 |
CWRX
| CWR TRANSPORTATION CO. | 1 |
DOTX
| USDOT/Federal Railroad Administration | 1 |
FTSX
| Fairmont Tamper | 2 |
HZGX
| Herzog Contracting Corporation | 3 |
LMIX
| Loram Maintenance of Way Inc. | 7 |
MBTA
| Massachusetts Bay Transit Authority | 4 |
MEC
| Maine Central | 1 |
MIX
| MIX | 1 |
NECR
| New England Central | 1 |
NNYX
| National New York Central Railroad Museu | 2 |
NPBL
| Norfolk and Portsmouth Belt Line | 1 |
NS
| Norfolk Southern | 102 |
NW
| Norfolk & Western | 19 |
PBNE
| Philadelphia Bethlehem and New England R | 4 |
PC
| Penn Central | 5 |
PTS
| PTS | 3 |
PW
| Providence and Worcester | 1 |
RBMN
| Reading Blue Mountain & Northern | 3 |
SCAX
| SOUTHERN CALIFORNIA REGIONAL RAIL AUTHORITY | 1 |
SCL
| Seaboard Coast Line | 1 |
SOU
| Southern | 13 |
SP
| Southern Pacific | 1 |
SRS
| Sperry Rail Service | 5 |
ST
| Springfield Terminal | 2 |
UP
| Union Pacific Railroad Company | 7 |