Update for beta testers
I have solved the problem of express/maimline trains whizzing onto minor tracks on their approach to BTM. It's taken a while for it to sink in to me, probably everybody else has been doing it for ages.
It's the train Priority Value that associates with the purple Priority track marks.
I have always set express/fast trains to value 1, but this give them permission to go wherever they like - and they do! I have used Via markers before but realised today that if I reverse the priority order mainline trains behave themselves perfectly.
This means you need to set your express passengers or trains needing to use main lines to Value 3 (not 1) and the mainline track also to Value 3.
Then put purple people eater markers on the relief lines and set those to value 1 and Bob's your Uncle! So any sidings in an inside curve like the Coal sidings need the entrance tracks set to V1, the right and left Norfolk tracks going and coming from/to the western portal also to V1. Basically any sidings you find passenger trains diving into really, there are a few. It means that when you send a goods out to a siding you will have to drive it, but if going to Bath, the west, the Docks and the Parkway portals then they set to Value 3.
I had this problem on WCL1 from Paddington and used Via track marks but doing it this way you don't need those.
Other than that the cdp hasn't changed much, a bit but not much.
Oh hang on. Trains incoming from the west refused to go into BTM platform 5 so I put an invisible signal on a short bit of track between points just before the platform starts. You will see where immediately, it needs a signal to let the train know the next set of points are correctly set. I found it because trains stopped at the signal gantry just after Bedminster and plonked a few invisible signals down to see if the train moved. It did, but I didn't want three signals so removed them one at a time untill I had the right one, the one on the crossing track. If you are unsure I'll send a piccie...
Other than that it runs well with 4/5 trains zooming about so I don't know why Stagecoach had problems. Probably had too many trains moving at once, he did state he 'flooded' the route with them.
Angela