Railroads have used computer aided dispatching for many years. The basic problem is GIGO - Garbage In - Garbage Out. The computer only does what it is told, so it tries to give priority to the expedited trains, and the dispatcher can override or change the priority to account for a crew running short on time or other considerations. The computer can only do what it is programmed to, and remember that most computer geeks doing the programming have no real clue what the railroad really requires. As pointed out, train lengths have increased and most railroads have turned switching anything into a painfully slow and inefficient process all in the name of cost reduction. Likewise the dispatcher's territories have been increased to the point where trains sit and wait for them to reply. The last thing you want to fall into is needing a dispatcher during turnover at shift change. The worst thing is to tone up the DS, and when they finally reply someone else jumps in ahead of you and then gets authority through what you need. By the time you get to say anything the DS is reluctant or doesn't have time to back their authority up so you can get your move done in front of them. Every now and then a good DS will call you first to see if you are ready to go before running the other train on top of you.

Until artificial intelligence reaches a much higher plane than it is now, a good DS can see now and the future, consider more variables and make far better decisions. The computer should be considered another tool to use not a replacement for a human capable of using their intelligence.