To operate Brett, I use a brilliant little Mac application called Switchlist.. available here.. I probably need to spend more time getting to grips with it, but in fairness, it seems to be providing me with the activity I was looking for. I suspect it was created with much bigger multi-location layouts in mind. However, I set up Fiddle Creek as my off-layout location and all the action happens between there and Brett.
I reckon that perhaps the best way to tweak this is to run through a number of sessions and get a proper feel to the balance, before rushing in and making changes to traffic numbers..
This is one of the screens used to alter the industries and cargoes..
You can also print off a number of reports (and even change the look of them to suit your company!)
I don't think that this app is available for Windows or Linux.