For youngsters, look into the Big John Rate case. In the 1960's Southern Railroad developed a new aluminium covered hopper car (nicknamed "Big John") that could handle significantly more grain than the common practice of using box cars. Southern applied to lower the rate but was stalled off for years by the Interstate Commerce Comission. As I recall Comission felt the lower pricing could hurt the competing barge industry. This was the motivation of the agency that was supposed to protect the shipping public from gouging railroads.

Part of this reregulation includes a discussion of open access where other operators could provide service over a railroad's own tracks. What motivation is there for the owner to invest scarce resources in keeping up their property if someone else is profiting from it?