Which is correct, “I am in the bus” or “I am on the bus”?

Which is correct, “I am in the bus” or “I am on the bus”?

If you are talking to a friend on your phone, explaining where you are at the moment, and you happen to be enjoying a ride on a common conveyance known as a bus, you would say, “I’m on the bus right now.” No one in his or her right mind would say, “I’m in the bus.”