I used to be the person to whom the complaints came about behaviour on buses. The company providing the private coaches for events etc also complained. It is dreadful. We resorted to having a member of staff riding shotgun which helped. A robust response from other passengers seems to work but I think many people are afraid to tackle bad behaviour by the youth these days for a number of reasons. But, without being defeatist, it isn't new. In our expat days over 30 years ago the DS travelled to their very expensive international school on the school bus. It was known as 'Hell on wheels' to all the parents. And back in England, one DS begged not to be sent to one of the very highly thought of local comps after a ten minute bus journey with a bus full of pupils from that school. If drivers successfully make the worst behaved get off the bus, the parents go to the press or the law and the driver is in trouble. I suppose what I am saying is that collective action is the only way of dealing with it.