All aboard!

Trains are a Tier 6 tech and become available for research after completing phase 2 of the space elevator (for Adequate pioneering).

This achievement can be unlocked by using a timetable to set up an automation for a train - albeit this is not really about timetabling nor scheduling; its really just a route/line definition with similar characteristics to what you'd see in a city builder game.

Note the achievement will pop just for setting the route - the train doesn't have to actually drive the route, and the route doesn't even have to work.