A persistent problem, one that gives a dark incentive against really using the existing parcel controls, is how traffic is parcel only and bears little reality to how a venue or community may be set up.
By giving groups with deeded land their own kind of traffic rating, this could help people to find communities that are active and have real footfall and activities. Exact methods on how to count traffic might be something for future discussions, but it's plain to anybody who has been here longer than a day, that the existing system is broken beyond repair and has been absolutely unusable in practise almost since its inception.
Communities join and follow groups, not land. Base traffic (and other things such as dynamic landmarks) on those groups. Keep the old system around for compatibility's sake and for people who for whatever reason refuse to adopt a better way, and give people looking for places to go a much more relevant way of doing so.