Urban Development Models

Why This Matters

Urban development models aren't just abstract diagrams—they're frameworks for understanding why cities look the way they do and who benefits or suffers from different growth patterns. When you're analyzing social problems like housing inequality, environmental injustice, or residential segregation, these models give you the vocabulary and conceptual tools to explain how spatial organization creates and reinforces social stratification. You're being tested on your ability to connect physical urban form to outcomes like displacement, access to resources, and quality of life.

These models also represent an evolution in how scholars and policymakers think about cities. From early 20th-century descriptive models to contemporary prescriptive approaches like Smart Growth, each framework reflects changing assumptions about transportation, economics, and social priorities. Don't just memorize the zones or features—know what social problem each model helps explain and what policy response it suggests.

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Classic Descriptive Models

These foundational models emerged in the early-to-mid 20th century as scholars tried to explain why cities organized themselves spatially. They describe patterns rather than prescribe solutions, but understanding them is essential for analyzing how urban structure creates unequal outcomes.

Concentric Zone Model

• Developed by Ernest Burgess (1920s)—based on Chicago, this model shows cities growing outward in rings from a central business district
• Five distinct zones reflect socio-economic stratification: CBD → zone of transition → working-class homes → middle-class homes → commuter zone
• Explains residential filtering—as wealthier residents move outward, housing "filters down" to lower-income groups, concentrating poverty near the urban core

Sector Model

• Proposed by Homer Hoyt (1939)—argues cities grow in wedge-shaped sectors rather than uniform rings
• Transportation corridors drive development—industrial, residential, and commercial uses extend outward along rail lines and highways
• Explains persistent inequality patterns—wealthy and poor sectors can remain stable over time as development follows established routes

Multiple Nuclei Model

• Introduced by Harris and Ullman (1945)—recognizes cities have multiple centers of activity, not just one downtown
• Reflects automobile-era decentralization—shopping centers, industrial parks, and residential clusters develop independently
• Better explains modern metropolitan complexity—useful for analyzing cities where activity is dispersed rather than centralized

Central Place Theory

• Developed by Walter Christaller (1930s)—explains the hierarchical distribution of cities based on the services they provide
• Larger cities offer more specialized services—smaller settlements depend on larger "central places" for goods like hospitals or universities
• Reveals urban-rural inequalities—helps explain why rural residents face barriers to healthcare, education, and economic opportunity

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Decentralization and Sprawl

These models describe the outward expansion of metropolitan areas, particularly after World War II. They help explain environmental degradation, car dependency, and the spatial mismatch between jobs and affordable housing.

Urban Sprawl Model

• Describes low-density, car-dependent expansion—characterized by single-family homes, strip malls, and separated land uses
• Creates significant social problems—traffic congestion, air pollution, social isolation, and inequitable access to services
• Raises sustainability concerns—inefficient land use consumes farmland and natural habitats while increasing infrastructure costs

Edge City Model

• Coined by Joel Garreau (1991)—describes suburban areas that become major employment and commercial centers
• Typically located near highway interchanges—featuring office parks, shopping malls, and entertainment complexes
• Shifts economic power from urban cores—can worsen inequality by concentrating jobs in areas inaccessible to those without cars

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Prescriptive Reform Models

Unlike descriptive models, these frameworks emerged as policy responses to the problems created by sprawl and automobile dependency. They represent deliberate attempts to reshape urban form for social and environmental goals.

Smart Growth Model

• Promotes compact, mixed-use development—aims to reduce sprawl by concentrating growth in existing urban areas
• Emphasizes sustainability and equity—protects open space, enhances public transit, and creates walkable communities
• Requires active policy intervention—zoning reform, growth boundaries, and community engagement are essential tools

New Urbanism

• Design movement advocating walkable neighborhoods—features diverse housing types, accessible public spaces, and human-scaled streets
• Prioritizes community and social interaction—rejects the isolation of suburban cul-de-sacs for connected, mixed-income neighborhoods
• Critiqued for sometimes enabling gentrification—new urbanist developments can raise property values and displace existing residents

Transit-Oriented Development

• Centers dense, mixed-use communities around transit hubs—typically within a half-mile radius of stations
• Reduces car dependency—promotes walking, cycling, and public transit as primary transportation modes
• Addresses spatial mismatch—can connect low-income workers to employment centers, but only if affordable housing is preserved near transit

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Urban Change and Displacement

This model focuses on the social consequences of neighborhood transformation, particularly how market forces and policy decisions create winners and losers in urban space.

Gentrification Model

• Describes neighborhood change when wealthier residents move into lower-income areas—property values rise, original residents face displacement
• Creates tension between revitalization and equity—improved infrastructure and services benefit newcomers while longtime residents lose housing and community ties
• Raises critical policy questions—should cities encourage investment that improves neighborhoods but displaces vulnerable populations?

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Quick Reference Table

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Self-Check Questions

1. Which two classic models both assume a single central business district, and what key factor distinguishes how they predict urban growth patterns?

2. Compare and contrast Smart Growth and New Urbanism: What problem do both address, and how do their approaches differ (policy vs. design)?

3. If an FRQ asks you to explain why low-income workers often struggle to access suburban jobs, which two models would you reference, and what concept do they illustrate?

4. How might Transit-Oriented Development and gentrification interact in the same neighborhood? What policy intervention could address the tension between them?

5. A city has multiple shopping centers, office parks, and residential clusters spread across its metropolitan area rather than concentrated downtown. Which model best describes this pattern, and what historical factor does it reflect?