1.1. Polycentric Region

Aus Pattern Language Wiki

01 01 Polycentric Region.jpg


... We need to establish a settlement area as it relates to a wider regional structure. This pattern governs the relation of urban centers to their peripheries.


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Problem-statement: Cities that are too centralized too often require excessive commuting from their edges, and their cores can become unhealthy monocultures.


Discussion: We can see that where cities and towns have developed in a more natural pattern — especially prior to the automobile — there has been a remarkably regular distribution of city sizes, with a few large urban centers, many smaller satellite towns, and a medium range of mid-size settlements, often suburban town centers. Similarly, most residents in these areas make a great many short trips — for example, daily trips to a nearby grocery store or to school — as well as a few long trips, perhaps to a major cultural event in another town. In between these extremes, they make a medium number of medium-size trips — for example, trips to work. This range of trip lengths could be illustrated this way:


01 02 Polycentric Region.jpg


But when a city is too centralized, even routine trips can become long commutes — for example, when the center is a monoculture of offices and workplaces, and the edges are primarily residential. By the same token, a city can also become too decentralized, with too many resources scattered across a large region, and requiring too much energy and cost for most people to access equitably.


A healthier pattern will include a more optimum distribution of activities and uses across settlements and scales, forming a “polycentric” region — a region with a range of diverse, mixed centers at a range of scales, each of which offers most of the routine destinations, activities and amenities of urban life.¹


This pattern can be seen clearly in the example of the London region (the photograph for this pattern). There a series of “urban villages” offers most of the needs for most residents to live, work and play within their own area, while they can also take longer trips less frequently. Some may make long frequent trips, but many do not.


This pattern also extends to the smaller cities and towns of a larger region. Their residents also need to be connected to the same regional economy, with similar life opportunities and exchanges, but focused more on the activities that are best suited for their regional location — for example, industries needing regular access to rail, water-intensive industries, or other location-specific economic activities.


What we describe goes to the heart of stable sustainable systems, which as evidence suggests, obey “fractal” scaling properties.² That means there are a few big elements, many small elements, and a medium number of medium-sized elements. In the case of path lengths, the same is true: there must be many more short trips, and many fewer long trips, made possible by the geometry of the urban fabric and its distribution of uses. Unfortunately in the 20th century, we created urban forms that forced too many longer trips, largely by separating functions with zoning. That was not a stable or sustainable condition.


All of these nodes in the local, regional and even global network, need to be well-connected and well-developed to provide balanced life opportunities for all residents. Evidence shows that when some populations are cut off from genuine opportunity for growth and human development, there are political, economic and environmental impacts for all populations that are likely to become unsustainable over time.



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Therefore:

Develop cities as nodes within polycentric regions, consisting of a range of sizes of mixed, diverse, well-connected “urban villages” that offer a full complement of daily and weekly needs, and good access to other parts of the region for less frequent trips.



01 03 Polycentric Region.jpg



Establish a rough structure of a 400M Through Street Network, creating continuous walkable and multi-modal urban areas. Where interruptions occur, such as natural geographic obstructions, connect the centers as much as possible with a continuous network, organized around the Mobility Corridor and Multi-Way Boulevard patterns…




¹ See for example the special issue of Urban Studies, Vol. 38, No. 4, and in particular the introductory essay, Kloosterman, R. C., & Musterd, S. (2001). The polycentric urban region: towards a research agenda. Urban Studies, 38(4), 623-633. Available on the Web at https://journals.sagepub.com/doi/pdf/10.1080/00420980120035259?casa_token=UN34U0vUJnMAAAAA:pIlcW55gb7HLO_J7IX8iPbyC3ASwQYp9oiBTjJtpcW1Hvyk7qu1s3rjBJj8q6aTUrfof-OuStj-a


² See for example Salingaros, N. (2005) “Connecting the Fractal City,” in Principles of Urban Structure. Amsterdam: Techne Press. Available online at http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.431.6038&rep=rep1&type=pdf



Mehaffy, M. et al. (2020). POLYCENTRIC REGION (pattern). In A New Pattern Language for Growing Regions. The Dalles: Sustasis Press. Available at https://pattern-language.wiki/.../Polycentric_Region



SECTION I:

PATTERNS OF SCALE


1. REGIONAL PATTERNS

Define the large-scale spatial organization…

1.1. POLYCENTRIC REGION

1.2. BLUE-GREEN NETWORK

1.3. MOBILITY CORRIDOR

1.4. 400M THROUGH STREET NETWORK

2. URBAN PATTERNS

Establish essential urban characteristics…

2.1. WALKABLE MULTI-MOBILITY

2.2. LEVEL CITY

2.3. PUBLIC SPACE SYSTEM

2.4. BIOPHILIC URBANISM

3. STREET PATTERNS

Identify and allocate street types…

3.1. URBAN GREENWAY

3.2. MULTI-WAY BOULEVARD

3.3. AVENUE

3.4. SHARED SPACE LANE

4. NEIGHBORHOOD PATTERNS

Define neighborhood-scale elements…

4.1. STREET AS CENTER

4.2. PEDESTRIAN SANCTUARY

4.3. NEIGHBORHOOD SQUARE

4.4. NEIGHBORHOOD PARK

5. SPECIAL USE PATTERNS

Integrate unique urban elements with care…

5.1. SCHOOL CAMPUS

5.2. MARKET CENTER

5.3. INDUSTRIAL AREA

5.4. HOSPITAL

6. PUBLIC SPACE PATTERNS

Establish the character of the crucial public realm…

6.1. PLACE NETWORK

6.2. WALKABLE STREETSCAPE

6.3. MOVABLE SEATING

6.4. CAPILLARY PATHWAY

7. BLOCK AND PLOT PATTERNS

Lay out the detailed structure of property lines…

7.1. SMALL BLOCKS

7.2. PERIMETER BLOCK

7.3. SMALL PLOTS

7.4. MID-BLOCK ALLEY

8. STREETSCAPE PATTERNS

Configure the street as a welcoming place…

8.1. STREET AS ROOM

8.2. TERMINATED VISTA

8.3. STREET TREES

8.4. STREET FURNISHINGS

9. BUILDING PATTERNS

Lay out appropriate urban buildings…

9.1. PERIMETER BUILDING

9.2. ARCADE BUILDING

9.3. COURTYARD BUILDING

9.4. ROW BUILDING

10. BUILDING EDGE PATTERNS

Create interior and exterior connectivity…

10.1. INDOOR-OUTDOOR AMBIGUITY

10.2. CIRCULATION NETWORK

10.3. LAYERED ZONES

10.4. PASSAGEWAY VIEW



SECTION II:

PATTERNS OF MULTIPLE SCALE


11. GEOMETRIC PATTERNS

Build in coherent geometries at all scales…

11.1. LOCAL SYMMETRY

11.2. SMALL GROUPS OF ELEMENTS

11.3. FRACTAL PATTERN

11.4. FRAMING

12. AFFORDANCE PATTERNS

Build in user capacity to shape the environment…

12.1. HANDLES

12.2. CO-PRODUCTION

12.3. FRIENDLY SURFACES

12.4. MALLEABILITY

13. RETROFIT PATTERNS

Revitalize and improve existing urban assets …

13.1. SLUM UPGRADE

13.2. SPRAWL RETROFIT

13.3. URBAN REGENERATION

13.4. URBAN CONSOLIDATION

14. INFORMAL GROWTH PATTERNS

Accommodate “bottom-up” urban growth…

14.1. LAND TENURE

14.2. UTILITIES FIRST

14.3. DATA WITH THE PEOPLE

14.4. INCREMENTAL SELF-BUILD

15. CONSTRUCTION PATTERNS

Use the building process to enrich the result…

15.1. DESIGN-BUILD ADAPTATION

15.2. HUMAN-SCALE DETAIL

15.3. CONSTRUCTION ORNAMENT

15.4. COMPLEX MATERIALS



SECTION III:

PATTERNS OF PROCESS


16. IMPLEMENTATION TOOL PATTERNS

Use tools to achieve successful results…

16.1. FORM-BASED CODE

16.2. ENTITLEMENT STREAMLINING

16.3. NEIGHBORHOOD PLANNING CENTER

16.4. COMMUNITY MOCKUP

17. PROJECT ECONOMICS PATTERNS

Create flows of money that support urban quality…

17.1. TAX-INCREMENT FINANCING

17.2. LAND VALUE CAPTURE

17.3. EXTERNALITY VALUATION

17.4. ECONOMIES OF PLACE AND DIFFERENTIATION

18. PLACE GOVERNANCE PATTERNS

Processes for making and managing places…

18.1. SUBSIDIARITY

18.2. POLYCENTRIC GOVERNANCE

18.3. PUBLIC-PRIVATE PLACE MANAGEMENT

18.4. INFORMAL STEWARDSHIP

19. AFFORDABILITY PATTERNS

Build in affordability for all incomes…

19.1. INTEGRATED AFFORDABILITY

19.2. COMMUNITY LAND TRUST

19.3. MULTI-FAMILY INFILL

19.4. SPECULATION TAX

20. NEW TECHNOLOGY PATTERNS

Integrate new systems without damaging old ones…

20.1. SMART AV SYSTEM

20.2. RESPONSIVE TRANSPORTATION NETWORK COMPANY

20.3. AUGMENTED REALITY DESIGN

20.4. CITIZEN DATA