| Abbreviation | Railroad Name |
| LAJ | LA Junction
|
| LW | Lackawanna
|
| LWVE | Lackawanna & Wy. Valley Elec
|
| LVAL | Lackawanna Valley
|
| LCM | Lake Champlain & Morian
|
| LEFC | Lake Erie, Franklin & Clarion
|
| LSI | Lake Superior & Ishpeming
|
| LSTT | Lake Superior Terminal & Trans
|
| LT | Lake Terminal
|
| LAKELAND | Lakeland
|
| LSMS | Lakeshore & Michigan Southern
|
| LSMB | Lakeside & Marblehead
|
| LAMV | Lamoille Valley |
| LCHS | Lancaster & Chester
|
| LANO | Laona & Northern
|
| LNPW | Laramie, North Park & Western
|
| LARY | Lary Trolleys
|
| LBGS | Laurinsburg & Southern
|
| LMS | Leace Manment Services
|
| LHR | Lehigh & Hudson River
|
| LNE | Lehigh & New England
|
| LV | Lehigh Valley
|
| LVT | Lehigh Valley Transit (elec)
|
| LYF | Lewistown&Youngstown Frontier
|
| LGIX | LGIX
|
| LIBMANN | Liebmann Packing
|
| LIGONIER | Ligonier Valley
|
| LIMA | Lima Locomotive Works
|
| LINDE | Linde Tank Cars
|
| LIONEL LIN | Lionel Lines
|
| LS | Liquid Sugars
|
| LITM | Litchfield & Madison
|
| LITTLERL | Little River Logging Co.
|
| LITTLE RIV | Little River Lumber
|
| LRWN | Little Rock & Western
|
| LOPG | Live Oak, Perry & Gulf
|
| LRC | Livingston Rebuild Center
|
| LAL | Livonia, Avon & Lakeville |
| LMX | LMX Leasing
|
| LNER | London North Eastern Rr
|
| LONG BELL | Long Bell
|
| LONG ISLAN | Long Island
|
| LI | Long Island RR
|
| LPN | Longview, Portland & Northern
|
| LWV | Lorain & West Virginia
|
| LASL | Los Angeles & Salt Lake (up)
|
| LAR | Los Angeles Rlwy |
| LAAR | Louisiana & Arkansas
|
| LONW | Louisiana & North West
|
| LOMD | Louisiana Midland
|
| LP | Louisiana Pacific |
| LOSO | Louisiana Southern
|
| LN | Louisville & Nashville |
| LOWD | Louisville & Wadley
|
| LONA | Louisville New Albany & Corydon
|
| LVRC | Louisville Railway Co |
| LODT | Lousiana & Delta
|
| LOBR | Lowville & Beaver River
|
| LUDN | Ludington & Northern
|
| LUNKEN | Lunken Steel
|
