| @private-us | Private owners group |
| AB | Akron Barberton Cluster Railway |
| ACE | Altamont Corridor Express |
| ACJ | Ashtabula Carson and Jefferson Scenic Railroad |
| ACL | Atlantic Coast Line Railroad |
| AERC | Albany and Eastern Railroad |
| AFTX | American Freedom Train Foundation |
| AGIX | AGRI Industries |
| AGPX | Ag Processing Inc. / Ag Processing Inc. |
| AKDN | Acadiana Railway |
| ALS | Alton and Southern Railway |
| AM | Arkansas and Missouri Railroad |
| AMTK | Amtrak National Railroad Passenger Corporation |
| APA | Apache Railway |
| ARR | Alaska Railroad |
| ARZC | Arizona and California Railroad |
| ASRY | Ashland Railway |
| ATSF | Atchison, Topeka and Santa Fe Railway |
| AUAR | Austin Area Terminal Railway |
| AVR | Allegheny Valley Railroad |
| AWRR | Austin Western Railroad |
| AZCR | Arizona Central Railroad |
| AZER | Arizona Eastern Railway |
| B&O | Baltimore and Ohio Railroad |
| BAP | Butte, Anaconda and Pacific Railway |
| BART | Bay Area Rapid Transit |
| BARX | Bartlett and Company |
| BDRV | Belvidere and Delaware River Railway |
| BH | B&H Rail Corporation |
| BJRY | Burlington Junction Railway |
| BLE | Bessemer and Lake Erie Railroad |
| BLKM | Black Mesa and Lake Powell Railroad |
| BN | Burlington Northern |
| BNSF | BNSF Railway |
| BPRR | Buffalo and Pittsburgh Railroad |
| BRC | Belt Railway of Chicago |
| BRG | Brownsville and Rio Grande International Railroad |
| Brightline | Brightline |
| BRW | Black River & Western |
| BSDA | MetroLink St. Louis |
| BTE | Ballast Tools Equipment |
| BUGX | Bruggere and Monson |
| C&O | Chesapeake and Ohio Railway |
| CAD | Cadiz Railroad |
| Caltrain | Caltrain - JPBX |
| CBFX | CITI Corp |
| CBQ | Chicago, Burlington and Quincy Railroad |
| CBRL | Coos Bay Rail Line |
| CBRY | Copper Basin Railway |
| CC | Chicago Central and Pacific Railroad |
| CCT | Central California Traction Company |
| CDTX | California Department of Transportation (Caltrans) |
| CEFX | CIT Equipment Finance Corporation |
| CEMEX | CEMEX |
| CFCR | Central Florida Commuter Rail - SunRail |
| CFE | Chicago, Fort Wayne and Eastern Railroad |
| CFNR | California Northern Railroad |
| CIC | Cedar Rapids and Iowa City Railway |
| CIM | Chicago and Illinois Midland Railway |
| CIRY | Central Illinois Railroad |
| CITX | CIT Equipment Finance Corporation |
| CLC | Columbia and Cowlitz Railway |
| CMNW | Chicago, Missouri and Western Railway |
| CNDX | Connecticut Department of Transportation |
| CNJ | Central Railroad of New Jersey |
| CNW | Chicago and North Western Transportation Company |
| COPR | City of Prineville Railway |
| CORP | Central Oregon and Pacific Railroad |
| CR | Conrail: Consolidated Rail Corporation |
| CREX | Citicorp Railmark (Citirail) |
| CRIP | Chicago, Rock Island and Pacific Railroad |
| CRR | Clinchfield Railroad |
| CRRX | Canon City & Royal Gorge Railroad / Canon City & Royal Gorge (Royal Gorge Route Railroad) |
| CS | Chessie System, Inc. |
| CSS | Chicago SouthShore and South Bend Railroad |
| CSXT | CSX Transportation |
| CTA | Chicago Transit Authority |
| CTN | Canton Railroad |
| CTSR | Cumbras & Toltec Scenic Railroad |
| CVSR | Cuyahoga Valley Scenic Railroad |
| CW | Colorado and Wyoming Rwy |
| CWR | California Western Railroad (Skunk Train) |
| CWRO | Cleveland Works Railway |
| D&SNR | Durango and Silverton Narrow Gauge Railroad |
| DAFX | United States Air Force |
| DAIR | D and I Railroad |
| DBGX | DeBruce Grain |
| DCR | Delmarva Central Railroad |
| DGNO | Dallas, Garland and Northeastern Railroad |
| DGVR | Durbin and Greenbrier Valley Railroad |
| DH | Delaware and Hudson Railway |
| DL | Delaware–Lackawanna Railroad |
| DL&W | Delaware, Lackawanna and Western Railroad |
| DLCX | Diesel Locomotive Company |
| DME | Dakota, Minnesota and Eastern Railroad |
| DMIR | Duluth, Missabe and Iron Range Railway |
| DOTX | Federal Railroad Administration |
| DPR | Deseret Power Railway |
| DRGW | Denver & Rio Grande Western Railroad |
| DRIR | Denver Rock Island Railroad |
| DRMX | Danbury Railway Museum |
| DRRV | Dover and Rockaway River Railroad Company, LLC |
| DSRC | Dakota Southern Railway |
| DTI | Detroit Toledo & Ironton Railway |
| DURR | Delaware and Ulster Railroad |
| DWP | Duluth, Winnipeg and Pacific Railway |
| eBART | East Contra Costa County BART extension |
| ECIX | Erman Corporation |
| ECRX | Trans-Global Solutions, Inc. |
| EJE | Elgin, Joliet and Eastern Railway |
| EL | Erie Lackawanna |
| EMDX | EMD |
| ESPN | East Penn Railroad |
| EV | Everett Railroad |
| EVWR | Evansville Western Railway |
| F&W | Fillmore & Western Railway Co. |
| FCEN | Florida Central Railroad |
| FCRD | First Coast Railroad |
| FCX | Freeport McMoRan |
| FEC | Florida East Coast Railway |
| FGLK | Finger Lakes Railway |
| FLJX | Big West Oil Company |
| FLNX | Flynn Incorporated d/b/a Ohio Railway Supply |
| FMID | Florida Midland Railroad |
| FTRL | Foster Townsend Rail Logistics |
| FURX | First Union Rail |
| FWRY | Fillmore and Western Railway |
| FWWR | Fort Worth and Western Railroad |
| GBRY | Gettysburg Railway |
| GBW | Green Bay and Western Railroad |
| GC | Georgia Central Railway |
| GCRX | Grand Canyon Railway |
| GDLK | Grand Elk Railroad |
| GECX | General Electric Company |
| GLC | Great Lakes Central Railroad |
| GLLX | Great Lakes Locomotive |
| GLR | Georgetown Loop Railroad |
| GLRX | Georgetown Loop Railroad / Georgetown Loop Railroad |
| GM&O | Gulf Mobile & Ohio |
| GMRC | Green Mountain Railroad |
| GMTX | GATX Rail Locomotive Group (GMTX) |
| GN | Great Northern Railway |
| GREX | Georgetown Rail Equipment |
| GRYR | Grenada Railroad |
| GSCX | General American Marks Company |
| GTW | Grand Trunk Western Railroad |
| GVRR | Grapevine Vintage Railroad |
| GWR | Great Western Railway of Colorado |
| GWWR | Gateway Western Railway |
| HESR | Huron and Eastern Railway |
| HLCX | Helm Leasing Company |
| HRRC | Housatonic Railroad |
| HRT | Hampton Roads Transit (The Tide) |
| HRY | Hawaiian Railway |
| HZGX | Herzog Contracting Corporation |
| IAIS | Iowa Interstate Railroad |
| IANR | Iowa Northern Railway |
| IATR | Iowa Traction Railway Company |
| IC | Illinois Central Railroad |
| ICE | Iowa, Chicago and Eastern Railroad |
| ICG | Illinois Central Gulf |
| IDTX | Illinois Department of Transportation |
| IERR | Indiana Eastern Railroad |
| IHB | Indiana Harbor Belt Railroad |
| IMRL | I&M Rail Link |
| IN | Indiana Northeastern Railroad |
| INRD | Indiana Rail Road |
| IORY | Indiana and Ohio Railway |
| IRM | Illinois Railway Museum |
| Ironton Railroad | Ironton Railroad |
| ISRR | Indiana Southern Railroad |
| ITC | Illinois Terminal Railroad |
| ITSX | In-Term Services ConGlobal |
| JCAC | Johnson County Airport Commission |
| JLCX | 564109 B.C. |
| KCS | Kansas City Southern Railway |
| KCSA | Kansas City Streetcar Authority / Kansas City Streetcar Authority |
| KCT | Kansas City Terminal Railway |
| KFR | Kettle Falls International Railway |
| King County Metro | King County Metro |
| KJRY | Keokuk Junction Railway Company |
| KTGR | Kingman Terminal Railroad |
| KYLE | Kyle Railroad |
| L&N | Louisville and Nashville Railroad |
| LACMTA | Los Angeles County Metropolitan Transportation Authority |
| LAL | Livonia, Avon and Lakeville Railroad |
| LCS | Leadville, Colorado and Southern Railroad |
| LDCX | Louis Dreifus Company |
| LDRR | Louisiana and Delta Railroad |
| LIRC | Louisville and Indiana Railroad |
| LIRR | Long Island Railroad |
| LLPX | Locomotive Leasing Partners |
| LMIX | LORAM Maintenance of Way |
| LMX | General Electric Leasing |
| LOCX | Lean and Green |
| LSRC | Lake State Railway |
| LTEX | LTEX Rail |
| LVRB | Lehigh Valley Rail Management |
| LVRR | Lycoming Valley Railroad |
| MALX | Mid-America Locomotive and Car Repair |
| MARC | Maryland Area Rail Commuter |
| MBTA | Massachusetts Bay Transit Authority |
| MCER | Massachusetts Central Railroad |
| MCR | McCloud Railway |
| MCRR | McCloud River Railroad Company |
| MDDE | Maryland and Delaware Railroad Company |
| ME | Morristown and Erie Railway |
| MERR | Maine Eastern Railroad |
| MET | Modesto and Empire Traction Company |
| METRO | Valley Metro Rail |
| Metrorail | Miami-Dade County |
| METX | Metra |
| MFAX | Missouri Farmers Association, Inc. |
| MHWA | Mohawk, Adirondack & Northern Railroad |
| MILW | Chicago, Milwaukee, St. Paul and Pacific Railroad |
| MJRX | Railway Service Contractors Inc |
| MKCX | Morrison Knudsen Corporation |
| MKT | Missouri-Kansas-Texas |
| MMID | Maryland Midland Railway |
| MMRR | Mid-Michigan Railroad |
| MNA | Missouri and Northern Arkansas Railroad |
| MNCW | MTA Metro-North Railroad |
| MNGRR | Maine Narrow Gauge Railroad Museum |
| MNJ | Middletown and New Jersey Railroad |
| MNN | Minnesota Northern Railroad |
| MNRX | Northstar Line |
| Moly-Cop | Moly-Cop |
| MP | Missouri Pacific |
| MQT | Marquette Rail |
| MRL | Montana Rail Link |
| MRSR | Mount Rainier Scenic Railroad |
| MSRC | MidSouth Rail Corporation |
| MTS | San Diego Metropolitan Transit System |
| MUNI | San Francisco Municipal Railway |
| MVPX | MOTIVE POWER RESOURCES INC. |
| MWCR | Mount Washington Cog Railway |
| MWRX | Midwest Rail |
| NBER | Nittany and Bald Eagle Railroad |
| NCMX | North Carolina Transportation Museum |
| NCRC | Nebraska Central Railroad |
| NCTD | Coaster commuter rail |
| NCTR | North Central Texas Railroad |
| NECR | New England Central Railroad |
| NJT | New Jersey Transit |
| NKP | Nickel Plate Road |
| NLR | Northern Lines Railway |
| NMRX | New Mexico Rail Runner Express |
| NOPB | New Orleans Public Belt Railroad |
| NP | Northern Pacific |
| NREC | National Railway Equipment Company |
| NRTX | WeGo Star (Music City Star) |
| NS | Norfolk Southern Railway |
| NSM | North Shore Mining Railroad |
| NSSR | North Shore Scenic Railroad |
| NTRY | Republic N&T Railroad |
| NVRR | Napa Valley Wine Train |
| NW | Norfolk and Western Railway |
| NWP | Northwestern Pacific Railroad |
| NYC | New York Central |
| NYGL | New York & Greenwood Lake Railway |
| NYMTA | New York City Subway |
| NYNJ | New York New Jersey Rail, LLC |
| NYSW | New York, Susquehanna and Western Railway |
| ODOT | Oregon Department of Transportation |
| OHCR | Ohio Central Railroad System |
| OMLX | Omnitrax Leasing |
| OPR | Oregon Pacific Railroad |
| ORHC | Oregon Rail Heritage Center |
| OVRR | Ozark Valley Railroad |
| OWTX | Oneida and Western Railroad |
| OWY | Oakway Leasing |
| PAR | Pan Am Railways |
| PBNE | Philadelphia, Bethlehem and New England Railroad |
| PC | Penn Central Transportation Company |
| PCC | Palouse River & Coulee City Railroad |
| PCCX | Peabody Coal Company |
| PESR | Potomac Eagle Scenic Railroad |
| PJRR | Port Jersey Railroad Company |
| PN | Pennsylvania Northeastern Railroad |
| PNWR | Portland and Western Railroad |
| Port of Montana | Port of Montana |
| PPCR | Pikes Peak Cog Railway / The Broadmoor Manitou and Pikes Peak Cog Railway |
| PRLX | Progress Rail |
| PRR | Pennsylvania Railroad |
| PRTD | Portland Railroad and Terminal Division |
| PS | Portland Streetcar |
| PTRA | Port of Houston Terminal RR Association |
| PTRC | Portland Terminal of Oregon |
| PVJR | Portland Vancouver Junction Railroad |
| PW | Providence and Worcester Railroad |
| RAFX | Rose Acre Farms |
| RBMN | Reading Blue Mountain and Northern Railroad |
| RCC | Ray-Carroll Co-Op |
| RCPE | Rapid City, Pierre and Eastern Railroad |
| RCRY | Raritan Central Railroad |
| RF&P | Richmond, Fredericksburg and Potomac Railroad |
| RGS | Rio Grande Southern Railroad |
| RJCP | R.J. Corman Railroad/Pennsylvania Lines |
| RJCR | R.J. Corman Railroad Group |
| RLCX | RELCO Locomotives |
| RLK | RailAmerica |
| RPRC | Richmond Pacific Railroad |
| RRC | RESPONDEK RAILROAD CORPORATION / RESPONDEK RAILROAD CORPORATION |
| RRRR | Rock & Rail |
| RRVW | Red River Valley and Western Railroad |
| RSSX | Railserve |
| RTD | Regional Transportation District |
| SB | South Buffalo Railway |
| SBCTA | San Bernardino County Transport Authority |
| SBD | Seaboard System Railroad |
| SBRR | Stourbridge Railroad |
| SBVR | South Branch Valley Railroad |
| SCAX | Metrolink Southern California |
| SCBG | Santa Cruz, Big Trees and Pacific Railway |
| SCCT | VTA Light Rail |
| SCL | Seaboard Coast Line Railroad |
| SCOX | Scoular Company |
| SCRT | Sacramento RT Light Rail |
| SDRX | Sound Transit |
| SEPTA | SEPTA Regional Rail |
| SERA | Sierra Northern Railway |
| SFBR | San Francisco Bay Railroad |
| SFS | Santa Fe Southern Railway |
| SGLR | Seminole Gulf Railway |
| SIT | Steam into History |
| SJVR | San Joaquin Valley Railroad |
| SLGW | Salt Lake Garfield & Western |
| SLRG | San Luis and Rio Grande Railroad |
| SLRS | SMS Rail Lines |
| SLSF | St. Louis & San Francisco Railway (Frisco) |
| SMART | Sonoma–Marin Area Rail Transit |
| SMV | Santa Maria Valley Railroad |
| SNC | Saratoga & North Creek |
| SOO | Soo Line Railroad |
| SOU | Southern Railway |
| SP | Southern Pacific Transportation Company |
| SPCC | Southern Peru Copper Corp |
| SPRS | South Park Rail Society / South Park Rail Society |
| SPS | Spokane, Portland and Seattle Railway |
| SPSR | San Pedro and Southwestern Railroad |
| SRC | Strasburg Rail Road |
| SRI | Steam Railroading Institute |
| SRR | Swan Ranch Railroad |
| SSLV | Southern San Luis Valley Railroad |
| SSW | St. Louis Southwestern Railway / The Cotton Belt Route |
| STE | Stockton Terminal and Eastern Railroad |
| SVGX | Savage Services |
| SVRR | Sacramento Valley Railroad |
| SWPX | Southwestern Portland Cement Company |
| TER | Texas Electric Railway |
| TMBL | Tacoma Rail |
| TNER | Texas Northeastern Railroad |
| TPW | Toledo, Peoria and Western Railway |
| TRC | Trona Railway |
| TRCX | Tri-Rail |
| TRE | Trinity Railway Express |
| TriMet | Tri-County Metropolitan Transportation District of Oregon |
| TRRA | Terminal Railroad Association of St. Louis |
| TRRA | Terminal Railroad Association of St. Louis |
| TSBY | Tuscola and Saginaw Bay Railway |
| TVA | Tennessee Valley Authority / Tennessee Valley Authority |
| TVRM | Tennessee Valley Railroad Museum |
| TZPR | Tazewell & Peoria Railroad |
| UP | Union Pacific Railroad |
| UPY | Union Pacific Yard |
| URR | Union Railroad |
| USAX | United States Army |
| USG | United States Gypsum Corporation |
| USMC | United States Marine Corps |
| USNPS | United States National Park Service |
| USSC | United States Sugar Corporation |
| USSX | US Steel |
| UTAH | Utah Railway |
| UTAX | Utah Transit Authority |
| VMVX | VMV Enterprises, Inc |
| VRE | Virginia Railway Express |
| VT | Virginia & Truckee |
| VTR | Vermont Railway |
| WAB | Wabash Railroad |
| WAMX | Webb Asset Management |
| WATC | Washington Terminal Company |
| WC | Wisconsin Central Ltd. |
| WCOR | Wellsboro and Corning Railroad |
| WCRL | West Chester Railway Lines |
| WDTX | Washington Department of Transportation |
| WE | Wheeling and Lake Erie Railway |
| WEMX | Western Milling |
| WER | Washington Eastern Railroad |
| WES | WES Commuter Rail / TriMet |
| WFAX | Western Fuels Association |
| WFS | West Isle Line |
| WMATA | Washington Metropolitan Area Transit Authority |
| WMSR | Western Maryland Scenic Railroad |
| WNYP | Western New York and Pennsylvania Railroad |
| WP | Western Pacific Railroad |
| WRIX | Western Rail Inc. |
| WRIX | Western Rail, Inc. |
| WSOR | Wisconsin and Southern Railroad |
| WSR | Warren and Saline River Railroad Company / Warren and Saline River Railroad Company |
| WTJR | Wichita, Tillman and Jackson Railway |
| WVR | Willamette Valley Railway |
| WW | Winchester and Western Railroad |
| YRC | York Railway |
| YVT | Yakima Valley Trolleys |
