Periodically, the Association of American Railroads (AAR), in consultation with industry experts, issues guidance on a wide range of topics related to rail transportation. This guidance is published in OT circulars. Below is a list of the circulars currently in effect as well as a list of expired circulars. Select a circular's number to view its contents.


Active Circulars

Number Origin Date Description and Issuing Officer Date Reviewed or Updated Effective Date Expired Date Oversight Committee
OT-2 12/1/81 Recommended Operating Practices for "Schnabel" and other Special Cars Equipped with Span Bolsters (Nichole Fimple) 12/27/13 11/1/12 Open EEC
OT-3 9/1/82 Timely and Accurate Reporting of Mileage Earned by Private and Railroad Owned Cars Operated on a Mileage Basis Of Compensation — Time Limit Within which Private Car Owners May File Claims (Nichole Fimple) 1/1/12 1/1/12 Open EAC
OT-5 7/1/89 Rules Governing Assignment of Reporting Marks and Mechanical Designations (Nichole Fimple) 12/12/19 2/1/20 Open EAC
OT-7 10/1/80 Uniform Application of Mileage Tariff Governing the Computation of Mileage Allowances on Cars of Private Ownership (Nichole Fimple) 1/1/12 1/1/12 Open EAC
OT-10 1/1/85 Code of Car Service and Car Hire Rules – Freight (Nichole Fimple) 7/1/12 Updated Monthly Open EAC
OT-16 3/1/87 Application of Transportation and car Hire Charges for Bad Order Cars, when Owner Responsibility or Handling Line Responsibility (Nichole Fimple) 1/1/12 1/1/12 Open EAC
OT-17 12/1/76 Recommended Practices for Inspecting, Testing and Repairing Industry Track Scales (Nichole Fimple) 4/1/13 4/1/13 Open EAC
OT-18 12/1/90 Recommended Operating Practices For Control of End of Train (E-O-T) Devices (Nichole Fimple) 8/12/21 8/12/21 Open EAC
OT-22 8/1/93 Recommended Reporting Standards for Shipments Moving under Car Haulage Agreements (Nichole Fimple) 1/1/12 1/1/12 Open EAC
OT-24 1/1/89 Rules Governing the Reporting of Valuation and Age Data on Freight Cars and Superstructures Bearing Railroad Reporting Marks for Car Hire Rate Purposes (Nichole Fimple) 1/1/12 1/1/12 Open EAC
OT-28 1/20/75 Short Line Connections (Nichole Fimple) 7/1/07 7/1/07 Open EAC
OT-34 7/1/84 Procedures for Reporting Car Grade (Nichole Fimple) 5/1/21 5/1/21 Open EAC
OT-36 1/1/84 Code of Trailer and Container Service and Reporting Rules (Nichole Fimple) 1/1/12 9/1/92 Open IC
OT-38 1/1/79 Description, Marking, Numbering and Reporting of Articulated Cars (Nichole Fimple) 11/1/12 11/1/12 Open EEC
OT-48 1/1/84 Instructions for Handling Damaged Tank Cars Stenciled "Home for Repairs—Do Not Load" (Nichole Fimple) 6/1/13 6/1/13 Open EEC
OT-49 2/10/75 Procedures for Notification of Operating Personnel in Connection with the Movement of FRA Defective Freight Cars Home for Repair (Nichole Fimple) 6/1/13 6/1/13 Open ARB
OT-55 8/23/01 Recommended Railroad Operating Practices For Transportation of Hazardous Materials (Mike Rush) 4/1/20 5/1/19 Open ESSC
OT-56 7/16/18 Compliance with Electronic Data Interchange requirements pertaining to advanced Interline Consist Transmission (Nichole Fimple) 7/16/18 7/16/18 Open EAC
OT-57 2/01/20 Registration of Contact and Storage Information for Private Cars (Nichole Fimple) 3/1/23 2/01/20 Open EAC
TD-1 1/01/75 Recommended Embargo Placement and Embargoed Traffic Handling (Nichole Fimple) 12/28/20 1/01/21 Open EAC


Archive of Expired Circulars

Number Origin Date Description and Issuing Officer Date Reviewed or Updated Effective Date Expired Date Oversight Committee
OT-6 9/1/81 Instructions Pertaining to The Movement of Cars of Private Ownership and Carriers' Responsibility for Mileage Caused by Railroad Error (J.J. Robinson) 2/1/12 9/1/81 2/1/12 EAC
OT-8 7/1/78 Uniform Application of Per Diem Rules to Cars Delivered Industries and Taken Out and/or Forwarded By Other Than The Delivering Road (J.J. Robinson) 9/1/12 7/1/78 9/1/12 EAC
OT-21 9/1/73 Experimental Load Cards (J.J. Robinson) 6/1/13 9/1/73 6/1/13 OTLRC
OT-23 11/1/81 Removal of Owner's Registered Reporting Marks Or Initials From Locomotives, Passenger, Freight And TOFC/COFC Equipment At Time Of Sale (J.J. Robinson) 5/15/13 11/1/81 6/1/13 UC
OT-26 6/1/81 Handling Loads of Dimensions in Excess of Published Clearances and Locomotives, Cranes and Industrial Equipment Moving on Own Wheels (J.J. Robinson) 6/1/13 6/1/81 6/1/13 OTLRC
OT-30 6/1/83 Rules Governing the Application, Inspection, Recording and Care of Car Seals (J.J. Robinson) 6/1/83 6/1/83 4/1/13 DPFC
OT-37 5/1/86 Supplemental Car Hire Charges for Rehabilitated Cars (J.J. Robinson) 2/1/12 5/1/86 2/1/12 EAC
OT-41 1/1/87 Track Scale Calibration Program by the Federal Grain Inspection Service—U.S. Department of Agriculture (Nichole Fimple) 6/3/11 6/3/11 4/12/22 AAR
OT-42 7/1/92 Uniform Mileage Format, Detail Report & Summary Reports for use in Reporting Data to Private Car Owners and Mileage Equalization for Private Tank Cars Per Mileage Tariff 7 Series (J.J. Robinson) 2/1/12 7/1/92 2/1/12 EAC
OT-44 9/15/80 Handling Loads of Extraordinary Value (J.J. Robinson) 4/1/13 9/15/80 4/1/13 DPFC
OT-53 9/1/83 Documentation Requirements for The Acceptance of TOFC/COFC Shipments (J.J. Robinson) 9/1/83 9/1/83 4/23/14 IOC
OT-54 11/21/85 Shipments of Hazardous Materials/Dangerous Goods to or through Canada (J.J. Robinson) 4/21/14 11/21/85 4/21/14 BOE