Liste des sigles de l'AAR débutant par U

U

• UBTX - Union Camp Corporation
• UCCX - Union Carbide Canada, Ltd.
• UCEX - Union Electric Company
• UCFX - Union Carbide Corporation
• UCLX - Vulcan Minerals Company
• UCOX - Union Carbide Corporation
• UCPX - Essem Corporation
• UCR - Utah Coal Route
• UELX - United Equipment Leasing Associates; Archer Daniels Midland
• UFIX - Utility Fuels, Inc.
• UIWX - Riley Stoker Corporation
• UMP - Upper Merion and Plymouth Railroad
• UMPX - Upper Merion and Plymouth Leasing Company
• UNI - Unity Railways
• UNCX - Union Carbide Canada, Ltd.
• UNPX - PROCOR
• UNSX - Unitrain Services
• UO - Union Railroad (Oregon)
• UOCX - General American Transportation Corporation
• UP - Union Pacific Railroad
• UPAX - United Power Association
• UPFE - Pacific Fruit Express; Union Pacific Railroad
• UPM - Union Pacific Railroad (Milwaukee Road directed operations)
• UPOZ - United Parcel Service
• UPP - Union Pacific Railroad
• UPRX - Union Pacific Fruit Express Company
• UPSZ - United Parcel Service
• UPWZ - United Parcel Service
• UPY - Union Pacific Railroad
• URDX - United States Steel
• URR - Union Railroad (Pittsburgh, Pennsylvania)
• URHX - United Railway Historical Societies of New Jersey
• URTX - General American Transportation Corporation
• URY - Union Railway of Memphis
• USAX - Département de la Défense des États-Unis
• USBX - GE Rail Services
• USCX - William G. Simon
• USEX - Evans Railcar Leasing Company
• USGX - Union Sugar Company
• USIX - US Industrial Chemicals Company
• USLF - Burlington Northern Railroad
• USLX - Evans Railcar Leasing Company; GE Capital Railcar Services
• USNX - Département de la Défense des États-Unis
• USPX - US Plastics Corporation
• USRX - U.S. Railways, Inc.
• USSX - United States Steel
• UTAH - Utah Railway
• UTAX - United Transportation, Inc.
• UTBX - Union Tank Car Company
• UTCX - Union Tank Car Company
• UTLX - Union Tank Car Company
• UTPX - Union Texas Petroleum Corporation
• UTR - Union Transportation
• UTTX - Trailer Train Company