The concept describes the evolution of American metropolitan areas based on transportation technology. It posits that urban growth is shaped by dominant forms of transportation during specific periods. Each epoch is characterized by a particular transportation technology that fosters unique patterns of urban development and spatial organization.
Understanding these epochs provides a framework for analyzing the historical development of cities and predicting future urban forms. The model emphasizes the interconnectedness of transportation advancements and spatial restructuring. By understanding the stages, one can identify how infrastructure investments and technological changes directly influence the physical expansion and social composition of urban regions.