Track Changes; Freight hauler CSX used to rely on masterly improvisers such as roy thigpen and charlie grady to get its trains through. Now, it has novices - and software.

Keith Triplett was clearly agitated.

In his 26th year on the job, the dispatcher for freight train operator CSX Corp. was worked up about losing one-third of the capacity at a key rail yard in his territory. Every day, the main track gets stopped up when a Chicago train pulls in, offloads its crew and then awaits new instructions. For hours on end.

Triplett has to figure out where to shunt trains bearing down on that track. Five more trains in a couple of hours, seven more behind those. He calls this "the Willard Shuffle," because the problem occurs at the rail yard in Willard, Ohio.

It's a dance Triplett thought should end with the advent of the company's new …