Model railways have come a long way in the last five years. I have the Roco Z21 system where you operate your locos on your phone or tablet via an app over wi-fi. They even provide a facsimile of the drivers cab and the controls operate as they would by touch as on the prototype rather than using the default control screen.
Locos are digital so no longer just picks up current from the track but a digital signal which operates the motor and other functions like momentum and sound features if your loco carries them.
Here's a run down of the system:
View: https://youtu.be/eOSfbwdzwy0