Making an app like "Metro"

[GreenBeanSoup]

good day,
I would just like to ask. What should I learn to be able to make an app like "metro". Where you just click your current train station and then your desired destination train station. And the app will tell you the shortest route.

Does this fall under the "traveling salesman" problem? Like what is the coding subject under?

Thanks.

 

[KnightNiwrem]

Why would you think this falls under the travelling salesman problem?

 

[Azzizz81]

Shortest path problem