Physical planning thought. Retrospect and prospect

City planning scholars recently have been calling for greater attention by schools of city and regional planning to the intellectual field of physical planning. This article responds by offering a retrospective of the physical planning field and a future research agenda. Both are organized around five perennial questions which, it is argued, have always been at the core of the field. The questions address the forces that shape physical development, the evolving urban form, possible and desirable physical futures, the impacts of development, and institutional means for guiding urban growth. The field has grown to include urban design and environmental planning. This is reflected in a current description of the 'physical city' which includes overall form, topography, buildings, infrastructure, transportation, utilities, open space, density, climate, vegetation, aesthetic quality, and urban design.