City centre blocks and their evolution: A comparative study of eight American and Australian CBDs

This article presents a comparative study of eight American and Australian city centres with different block forms in their initial layouts. The study analyses the physical evolution of these centres since their foundation as small settlements in the nineteenth century. It examines the changes that have occurred in block forms, circulation patterns, land parcelling, building forms and land use; identifies the processes and factors involved; and demonstrates how these were influenced by initial block forms. It found that some block forms and sizes were better than others in making city centre layouts more amenable to adaptation, or more robust in meeting varied development needs over time. Such knowledge can guide future evolution of city centres towards adaptable block forms with predictable performance characteristics.