That what i also thought.
But maybe it's MC's current technical abilities that would be the limiting factor?
I mean, for a train, all you need is a track and an powerful engine which just moves forward.
For an Airship, you also need other stuff, like how to make the object float up and go down, or how to move an object without friction and at a stable balance, etc.
On another note, the distance is roughly 590 KM (367 Miles).
Unless the train that MC makes runs over 200 KM per hour (meaning atleast under 3 hours of travel time), it would take a long time for Liz to be able to commute between the two cities.