The car free street group in our area organised a diversion down streets which usually carry no traffic, which was a bit annoying as drivers have now learned a new rat run and continue to use it.
They could have been directed back onto the main roads instead.
One thing that's always good is to tie a car-free day to a concrete outcome to be achieved. In your case, that could be one of filtering in that area. The group could have discussions with the council and plan the next CFD in that way.
The car free street group in our area organised a diversion down streets which usually carry no traffic, which was a bit annoying as drivers have now learned a new rat run and continue to use it.
They could have been directed back onto the main roads instead.