CaTrain is a tool for designing, simulating, and controlling model railways. The design mode allows the user to draw a simplified layout, including devices such as turnouts, signals, and level crossing. The running mode permits the checking of the layout by concurrently running several trains on it. The trains that have been installed on the railway are animated on the screen.

The trains can either circulate under manual control or automatically, following user-defined itineraries. Automatic mode controls the journey, the schedule, and the track contention for every train while setting the turnouts and the signals as required. When the PC is connected to a dedicated controller, CaTrain can control a real model railway.