The GCOR rules are intended to enhance railroad safety. The rules cover employee responsibilities, signaling equipment, procedures for safe train movement, dealing with accidents and other topics that directly and indirectly affect railroad safety. Some railroads modify the GCOR rules to suit their specific operations.
The GCOR is supplemented by System Special Instructions, Timetables, Hazardous Materials Instructions, Air Brake and Train Handling Instructions, and General Orders. These documents are issued by each individual railroad. System Special instructions, Timetables, and General Order can modify or amend the General Code of Operating Rules. GCOR 1.3.2 states that General Orders replace any rule, special instruction, or regulation that conflicts with the general order.[2]
Some railroads will maintain what they call a "living rulebook." As amendments are released via general order or special instruction, they will update the specific page that was affected.[1] An example of this is the Union Pacific, which maintains a copy of the GCOR with page-by-page amendments.[3]
The current version of the GCOR is the Eighth Edition, effective April 1, 2020.[4]