Not sure if this can be helpful, but your post reminded me of a Tweet by @redgeographics I saw last month. Might want to contact Hans anyway, as he is the cartography expert!
I am actually working on a solution for this:
It's currently work-in-progress, I don't think there will be a "perfect" solution, but right now it's "pretty darn close" with "a few seconds" of processing time for a fairly large public transit network.
It will most likely be a custom transformer that I'd be exploiting commercially, so you would have to buy a license from me.
Hi @redgeographics
that sounds great! Can you estimate when it will be ready? Would be nice if I could send me an email adress how I can contact you.
Best wishes
Thomas
I don't think it will ever be "ready", right now it does not handle very complex situations all that well and it really depends on how clean the source data is, I tried it with some bus lines taken from OpenStreetMap, bad idea... but my other sample set is fairly clean and it does come up with decent results there.
The way I see it, it will most likely always be one of those solutions that works well for x % of the time but still requires some manual touch-up in the graphics design phase. Key now is to get that % as high as possible.
If you want you can reach me at hans@redgeographics.com, I'd be happy to take a look at any sample data you'd be able to provide.