Can you tell me the mileage of your car?
Leaving your seat while the bus is moving is dangerous.
The train will start running to Hogwarts School of Witchcraft and Wizardry again as soon as the strike is over.
A vehicle that run-goes is running and it's moving you somewhere else. You're traveling!
We usually use this word to describe moving or running vehicles like cars and trains. Keep an eye on those context sentences to make sure you're using it right. ;)
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.