AMTK
| Amtrak | 2 |
ATSF
| Atchison Topeka & Santa Fe | 2 |
BM
| Boston & Maine | 2 |
BNSF
| BNSF Railway | 5 |
BO
| Baltimore & Ohio | 5 |
BRTX
| BRTX | 4 |
CEI
| Chicago & Eastern Illinois | 1 |
CN
| Canadian National Railways | 185 |
CNW
| Chicago & Northwestern | 1 |
CO
| Chesapeake & Ohio | 14 |
CPMY
| Coopersville & Marne Railway | 4 |
CR
| Conrail | 1 |
CSX
| CSX Railroad | 54 |
DIR
| DIR | 2 |
DRGW
| Denver & Rio Grande Western | 1 |
EL
| Erie Lackawanna | 1 |
ERIE
| Erie Railroad | 6 |
GN
| Great Northern | 5 |
GT
| GT | 1 |
GTW
| Grand Trunk Western | 4 |
HABX
| Habco International Incorporated | 1 |
HTT
| Harsco Track Technologies | 3 |
HVRM
| HVRM | 16 |
HZGX
| Herzog Contracting Corporation | 22 |
IATR
| Iowa Traction Railroad Company | 2 |
IC
| Illinois Central | 7 |
IHB
| Indiana Harbor Belt | 14 |
KCL
| KCL | 1 |
LMIX
| Loram Maintenance of Way Inc. | 38 |
LN
| Louisville & Nashville | 1 |
METX
| METRA | 3 |
MILW
| Milwaukee Road | 15 |
MKT
| Missouri-Kansas-Texas | 3 |
MNTX
| Minnesota Transportation Museum, Inc. | 7 |
MON
| Monon Route | 4 |
NICD
| Northern-Indiana Commuter Transportation | 33 |
NKP
| Nickel Plate | 5 |
NOTM
| NOTM | 1 |
NP
| Northern Pacific | 3 |
NS
| Norfolk Southern | 43 |
NW
| Norfolk & Western | 29 |
NYC
| New York Central | 2 |
NYSW
| New York Susquehanna & Western | 1 |
OBB
| OBB | 9 |
PACX
| Plasser American Corporation | 1 |
PRR
| Pennsylvania Railroad | 6 |
RCRX
| Reagent Chemical and Research Incorporated | 5 |
RFP
| Richmond Fredericksburg & Potomac | 1 |
RRVW
| Red River Valley and Western Railroad | 9 |
RWKX
| RWKX | 10 |
SOU
| Southern | 3 |
SP
| Southern Pacific | 1 |
SPSX
| Progress Rail Services Corp | 6 |
SRS
| Sperry Rail Service | 1 |
SSW
| St Louis Southwestern (Cotton Belt) | 1 |
TRBX
| TRBX | 1 |
TYOX
| The Tie Yard Of Omaha Inc. | 7 |
UP
| Union Pacific Railroad Company | 35 |
UV
| UV | 1 |
VGN
| Virginian Railway | 7 |
WM
| Western Maryland | 3 |