I've not researched this properly yet, but I'm posting this as a starting point for discussion, and I'll probably revisit it later... I'd quite like a route with Request stops. For those not familiar with this these, they are stations where the train doesn't stop by default. If you're on the train, you tell the guard you want the train to stop; if you're on the platform, you stick your arm out like hailing a cab/bus. I like the idea of having to watch out for a person, or listening for a buzzer from the guard, would add a bit of uncertainty to the route. I think the North Warwickshire (or Shakespeare) line has 4 request stops: Danzey, The Lakes, Wooten Wawen and Wood End, so that would be a good choice. However, there are about 150 such stations in the UK, so there are plenty of other lines that would suffice.
It was the start of it. I didn't know there were so many on "normal" lines. I know a lot of the heritage lines have them, but not a suburban service in Brum.
http://geofftech.co.uk/download/RequestStops.pdf Geoff's list of request stops...138 in total across the UK including many on the North Wales Line (not implemented in TSx, maybe in TSW?), but most likely routes in TSW would be the Breckland and Wherry Lines were there are 5 total
They are common in Switzerland too, some trains even have stop request buttons. Thomson have implemented it on some of their Swiss routes.
Quite a few on the Barnstaple-exmouth tarka line too. I always wondered how the driver manages to stop in time
I imagine the speed limits for services that might stop at those stations are reduced and drivers should expect to stop