CR
| Conrail | 4 |
GCT
| GCT | 1 |
LMIX
| Loram Maintenance of Way Inc. | 10 |
MP
| Missouri Pacific | 1 |
MTA
| NYC Transit | 2 |
NJT
| New Jersey Transit | 3 |
NW
| Norfolk & Western | 1 |
NYSW
| New York Susquehanna & Western | 4 |
SPSX
| Progress Rail Services Corp | 3 |
SRS
| Sperry Rail Service | 2 |
UP
| Union Pacific Railroad Company | 1 |