Cyburbia is a friendly big tent, where we share our experiences and thoughts about urban planning practice, the built environment, planning adjacent topics, and anything else that comes to mind. No ads, no spam, and it's free. It's easy to join!
Simplistic though not simple answer: Garden Cities
Buy a ring of inviolate open space around the community thereby forcing growth to begin in a new community beyond the ring. Of course this works great in "new" communities. Its a little tough in existing communities that have already sprawled. (I said it wasn't simple).
I believe I threw the concepts of carrying capacity and
optimum size on the table---or on the web site, as we say
today. But like others on this site, Jeff you raise the hard questions.
Optimum itself can mean different things to different people.
But assuming that some of the traditional concepts of optimum city size could be refined and updated, I would think the best way to achieve such a community would be
through consensus----through a shared vision that various factors including health, safety, and welfare, and carrying capacity, could be served by some optimum figure or range.
A widespread desire to develop, or redevelop, communities which work well.
John's idea of open space bands, etc. might help.
I think our mass media are running out of ideas---i.e. the surge in "reality" and "survivor-contrived" type shows.
Some big planning, and "City beautiful" type effort, headed by a communicators like the late Carl Sagan and the sports icon Michael Jordan, could excite people about the possibilities of living in optimum communities.
There is heavy marketing of all kinds of trinkets and short-lived gadgets, etc. Why not the communities where we are born, get married, work, and have children and so on.
Amazing what kind of thoughts come to mind when one lives in total 24-hour daylight for almost three months every year! Share the dream!