AIBU to be concerned about young children on council-provided school bus with no adult supervision?

[Gertrudethechicken]

My DD is 5 and has recently started travelling to/from school on a council-provided school bus. There is a driver, but apparently no passenger assistant/chaperone on the bus. Yesterday she told me that an older boy on the bus tried to spill his juice over her. She said he was deliberately trying to do it, rather than it being an accident.
I know children messing around on buses isn’t exactly unusual, and I’m not suggesting this particular incident is some huge safeguarding crisis. But it has made me think about the fact that she’s only 5, travelling with considerably older children, and there doesn’t appear to be anyone supervising them other than the driver.
The driver obviously needs to concentrate on driving, so realistically they can’t be watching what’s happening further back on the bus.
I’m wondering whether I’m being unreasonable to think that a bus carrying 5-year-olds alongside older children should have some form of adult supervision? She’s my first so fully prepared to be told I’m being precious or over the top.

rural Scotland for those asking

I grew up in rural Scotland. When I started going to school age 5 there were only a few large buses that did long convoluted routes. We lived 3 miles from the school but I had an hour long trip home from school and was the last one dropped off. My parents said I was so shattered at the end of every school day that they decided to change things and spoke to everyone they knew who owned a minibus and asked them to apply for the school bus contracts the next year, as a result my trip home changed from an hour to 5 minutes, that primary school still uses minibuses. But also, a minibus with 8 kids in it is much easier to control the behaviour than a coach with 50 kids on it.

what a clearly untrue and incredibly pointless statement.

It was clearly sarcasm.

My daughter got a private bus to school from the age of 4 ( a group of parents paid for it from a coach company). No chaperone. First driver would not have intervened with poor behaviour. 2nd driver did. The rule was youngest children at the front, oldest at the back which prevented the kind of behaviour op has described. You need to speak to the driver/school about putting some rules in place.

What?? You shock me. I never would have guessed.

Have you never heard of sarcasm?

No - what is it?