I have always been fascinated by this machine that you can still find in some Parisian subway stations. Press and hold the button corresponding to your destination (on the keyboard) and your trajectory lights up (this one was not working). I haven’t spent enough time figuring out if it shows you the shortest trajectory, or a trajectory that has the less connections. Bruno… Would you have any insight?

Definitely in the lineage of the GPS… though this one is not portable :)