I'd have two categories of scare zone.
The first would be effectively what we have now: main pathway areas where, while some scareactors are able to get in some scares, they are more atmosphere/entertainment focused. Then, in slightly smaller, areas that are off of main paths, you'd have slightly more scare focused zones that are halfway between a house and a zone.
Probably something along the lines of Plaza of the Stars, Hollywood, NY (Specifically the parade Route area in front of Mummy) and San Fran for the first type, and then KidZone, The Road between Transformers and New York, The Road Between Transformers and Shrek, the London Waterfront (the pathway along the water specifically) and maybe another path in the FF/MiB/Springfield area for the latter.