Its a 4 lane roundabout, You would be a moron if you wanted to walk there.

My understanding is all of central MK pedestrians are not allowed on roads, with signs such as this being common: https://www.reddit.com/r/fuckcars/comments/s1pehz/this_sign_in_central_milton_keynes_in_the_uk_a/

I would call that legal access is denied for foot traffic.