would you be OK about this road?

[Feelingsensitive]

I am in the process of applying for reception for my DD. Our nearest school has an outstanding ofsted and everyone is making all the right noises about it. I've looked at it and I like it except for one thing. The playground is small with very little grass (we are in London). One one side of the playground there is a very high wall (about the height of a 4 storey building I would guess) which leads to a very busy 4 lane road. Not sure if I am explainging this well but if you were on the said road and looked down, there would be the school. In addition it has a main road running along the front. I can't help but think all that pollution can't be good. Am I being barmey about this? I have 3 choices to put on the form. The other two have lots of grassy play areas and are on normal roads but are further away. They also have less favourable ofseted reports and SAT results but still OK. Should the environment (by which I mean where the school is situated) be as important as ofsted and all that?

Realistically how much time will she spend being exposed to the road? I suppose I'd want as much green as possible, but, if compromise meant a better start to my dd's school career I think I'd compromise.

I wouldn't like it. Reception is all about inside and outside play being free-flowing and they could be outside for 3 or 4 hours, including lunchtime. What if there was a major accident - could cars tumble into the playground? Sorry if that sounds bizarre I'm trying to imagine what the school looks like!
Can you hear road noise inside? And what about in the summer when the windows are open?

Can you still within walking distance of the other schools? If so, I think I'd prefer them.

I asked about potential accidents and they said it had been assessed and not a problem. They have put barriers up but I still think there is a possibility of a freak accident but thats probably my mum paranoia. Its quite noisy in the playground but I don't remember hearing road noise when we were inside. One of the other schools is walking distance and the other isn't. The one that isn't is in a much nicer area where all the children would be from middle class 'nice' families. That would be its biggest pro for me (I am a snob ) as the distance is a problem.