A train is like a big wagon that moves along special tracks. A person called a train driver is in charge of making sure the train goes where it needs to go.
The train driver watches special lights called traffic lights and something called semaphores. These are like signs that tell the train when to go, when to stop, and when to be careful. Just like when you play on the road, we have to follow the rules and signals to keep everyone safe!
So, when the train driver sees a red light, that means 'stop!' When they see a green light, it means 'go ahead!' The train driver knows all these rules and follows them to drive the train safely along its special route.