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, including Uniform Application of Mileage Tariff Governing the Computation of Mileage Allowances on Cars of Private Ownership (Nichole Fimple) | 3/1/25 | 3/1/25 | 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-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) | 1/1/24 | 1/1/24 | 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) | 3/1/25 | 3/1/25 | 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 | 2/1/20 | Open | EAC |
| TD-1 | 1/01/75 | Recommended Embargo Placement and Embargoed Traffic Handling (Nichole Fimple) | 1/2/24 | 1/1/21 | 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-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 | 3/1/25 | 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 |
