Ah, I see where your confusion is. A path that goes through a locked door is NOT a path. The Zombies will never take it into account if they have the possibility of getting to the noisiest Zone by a different, open, path. The ONLY case where Zombies will try to take a path through a locked door, and end up stuck behind it, is if there are NO other open paths available.
So in your case, the Zombies in 1 would move into the building, and the Zombies in 2 and 3 would move into the street intersection Zone with the police car.
So in your case, the Zombies in 1 would move into the building, and the Zombies in 2 and 3 would move into the street intersection Zone with the police car.