when the train service is closed

Yes, they are fine, WB. I think that finished or shut down are more natural than closed.

"Not running" is quite common where I come from.

Thank you~

You mean the train service can be RUNNING rather than the TRAIN?

Exactly

We can say:

The train service runs from 6:00 to 23:00
The train service stops at 23:00
After the train service stops/stops running, you will have to use a taxi to get home.
When the train service is not running, the railway workers can inspect the track/you will have to take the bus/getting to work is difficult

Thank you~