To think if your 9 year old has already had 2 'fights' with a bus.....

[BadDayAtTheOrifice]

..you wouln't continue to let them ride their bike to school on their own?

Last week, I saw a boy in DD's class with his cheek all swollen and bruised. DD tells me he's had a 'fight' with a bus whilst crossing the duel carriageway(!) on his way to school. It has been the second time he's been involved in an accident, apparently. He's only been riding his bike to school since Christmas.
Anyway, I see him today, on his bike, riding home alone. AIBU to be concerned for his safety?

That is a situation that I would report to his school and let their safeguarding team look at the situation.

Sounds distinctly dodgy, buses generally take no prisoners!

I'd say have a word with the school too, our primary had fairly strict guidelines on kids coming in on their own transport ...

How old is he and has he done a Bikability course?

Not a chance that my DC would be riding to school, one fight would be sufficient to convince me of that.
My dolly daydream DD has done a bikeability course. She just about squeaked a pass.
The instructor told me not to let her out on the road without supervision.

I wouldnt be letting them near a bike alone.

I am sure it has raised some alarm bells with the school

I would check with the school that they are aware of the concerns. I also take a dim of view of parents allowing their child to make their own way to school when it involves the crossing of a dual carriageway road. I am 35 and an experience town cyclist and I wouln't like doing that!

Those poor bus drivers.