How much time will you be spending in the flat as opposed to enjoying the amenities, OP?
There's a similar parade of shops with flats above on a main road near me. It has reasonably heavy traffic but the worst noise is from two busy pubs. They're not terribly raucous but there's only so much the landlords can do.
I don't know what it's like where you are but in the road I'm thinking of, the noise wouldn't bother anyone who wanted to go to bed after midnight. After then, it's pretty much dead. I think even if you wanted to sleep before then, you'd probably get used to it unless you were particularly sensitive. The worst thing is the Tesco Metro which I guess gets deliveries from 6am.
I'm two streets away. It's like the grave where I am.