Last night I finished a scenario for the South London - Brighton route, the 6Y60 Ardingly- Hither Green empties, set in 2012 with a EWS 66 and 18 JHA wagons. I had two minds weather to start at Haywards Heath or Ardingly and attempt the run around, which I thought would be a headache in its own right, seeing as its pathed out 13 minutes ahead of a London fast, and also requires the player to stop further down from Platform 1 at Haywards Heath as per reality as the consist is too long to fit in the platform, and you need to be clear of the rear signal as this would be the starter signal.
I went for starting at Ardingly, built the required AI around Haywards Heath, set the run around and ended the path at Three Bridges, and gave it a test run just to see how it worked.
To my surprise it worked! I still had the problem of deciding how to tell the player where to stop at Haywards Heath, but I got around that my placing a workman in high viz object at the point where you should stop.
Next would be following a bunch of services through London but already looking at the Working Timetable I could see another problem. Because it runs via Clapham, Polparts, Longhedge and Wansworth Road, it needs to run on the Fast from Balham.
The route is via Crystal Palace and Streatham Hill, but the challenge is crossing onto the fast with a rough 3 - 4 minute gap to slot in on the fast line.
I had no faith whatsoever with the dispatcher, I could see all sorts of problems, mostly by sitting at the junction waiting for lots of AI to pass that I should be seeing at Clapham. My service class was 'Express Freight' so that the freight speeds would appear, but also to stop it running through every goods loop it sees.
At the signal before the junctions at Balham, I set a siding marker and called it Streatham Hill sig VC160 (or whatever the number was I can't remember off hand). and had it as a timed location from 1100 - 1104 hoping it would work.
I had to set another near Factory Jn to hold the player there otherwise the dispatcher sends you through too early.
The scenario ends at Nenthead, and is 2 hours long in total. I had my first full test drive last night and was not confident at all. I was waiting for an AI derailment pop up, or a mess up at Balham.
Apart from being routed through Redhill P2 and the North loop (which I've now fixed) the whole thing ran as it should have!

I've set the difficulty to hard, mostly because of the run round, lots of yellows, and signal location markers which means the player does need to run roughly on time for it to work.
But I was thoroughly amazed it worked first time! It was a gamble as I spent a whole week building it (evenings after work and most of the weekend) and hoped all that time wasn't to waste, and it wasn't.
Something so complicated worked wonders, yet my last project, which was a simple A - B run, I ditched as I had all sorts of problems trying to follow a Gatwick Express, and the dispatcher wasn't having it!

James