The City of Irvine is one of the best examples of a successful, master planned community in the United States. Recently its owner, Donald Bren, was interviewed about land planning and development. The following answer was one I found interesting.
Can Irvine be duplicated elsewhere in the future?
Donald Bren: The government regulatory and environmental restrictions have become so overwhelming for large-scale projects that they are not feasible going forward… There is little opportunity to problem solve and get on with the business of new development. Government regulatory and environmental restrictions at the local, regional, state and federal level are just overwhelming, not to mention the numerous legal challenges that follow.
The entire interview is pretty interesting. You can watch it here.