I just wanted to add this idea, as it could be implemented easily without a total change to the system.
Change Milestones / Travel Posts to be individually named, instead of the road itself.
This aims to get rid of any confusion when selecting routes.
I'd love to see a window open up for the road selection, rather than the flower menu that we have currently. And possibly even a scroll-able mini-map at the top of the window, but that's not entirely necessary if it were leagues more difficult.
This is a rough design I made in about 5 minutes, if anyone wants to take this idea and expand on it or clean it up, be my guest.
Thanks.