Does TSW2 keep track of the scenarios/sessions I've completed on all routes in a single location that I could consult without having to check routes one at a time?
That would be a nice thing, but have never stumbled onto anything like this, only the individual routes show which scenarios you have run.
You can do that but I think that Last Train to Clarksville wants something that would show each route and scenarios driven on that route. The log is a chronological listing which you have to scroll through to find what you have driven.
I'm afraid there is no such thing. Neither in TSW2 nor in your drivers logbook do you get a nice overview of all available scenarios and which you have driven or not. Technically speaking, your local save file should store everything. I am however not aware of which values do mean what and there are a lot of values in this savefile. Also opening the save file is not as easy as opening a file in notepad.