Polycentricity and Sustainable Urban Form An Intra-Urban Study of Accessibility, Employment and Travel Sustainability for the Strategic Planning of the London Region Duncan Alexander Smith Centre for Advanced Spatial Analysis & Department of Geography University College London A thesis submitted for the degree of Doctor of Philosophy (Ph.D.). Revisions submitted August 2011. 1 Declaration of Authorship I, Duncan Alexander Smith, confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated in the thesis. Copyright © Duncan Alexander Smith 2011 2 Abstract This research thesis is an empirical investigation of how changing patterns of employment geography are affecting the transportation sustainability of the London region. Contemporary world cities are characterised by high levels of economic specialisation between intra-urban centres, an expanding regional scope, and market-led processes of development. These issues have been given relatively little attention in sustainable travel research, yet are increasingly defining urban structures, and need to be much better understood if improvements to urban transport sustainability are to be achieved. London has been argued to be the core of a polycentric urban region, and currently there is mixed evidence on the various sustainability and efficiency merits of more decentralised urban forms. The focus of this research is to develop analytical tools to investigate the links between urban economic geography and transportation sustainability; and apply these tools to the case study of the London region. An innovative methodology for the detailed spatial analysis of urban form, employment geography and transport sustainability is developed for this research, with a series of new application of GIS and spatial data to urban studies. Firstly an intra-metropolitan scale of spatial analysis is pursued, allowing both an extensive regional scope and a sufficiently intensive local level of detail to analyse the decentralisation processes described above. Secondly a series of detailed spatial datasets are introduced to analyse employment geography and dynamics, including business survey data and fine- scale real-estate data. For the measurement of accessibility, detailed network analysis and congestion data is used. Finally for the assessment of transportation sustainability, an indicator of CO2 emissions at intra-urban scales is developed, and is calculated for the 6.5 million journey-to-work trips in the study region. The results highlight extreme intra-urban variation in accessibility, employment geography and travel carbon emissions with clear relevance to urban form and sustainable travel debates in the London region. 3 Table of Contents List of Figures 6 List of Tables 8 Acknowledgements 10 Introduction 12 1 Accessibility, Agglomeration and the Evolution of Urban Form 20 1.1 The Evolution of Urban Spatial Structure 21 1.2 The Form of the Contemporary World City 37 1.3 Chapter Conclusions 44 2 Urban Systems and Location theory 46 2.1 Land Use Transportation Interaction 47 2.2 The Micro-Economics of Firm Location 55 2.3 Chapter Conclusions 67 3 Sustainable Transportation and Urban Form: Principles and Evidence Base 69 3.1 Sustainable Urban Planning 70 3.2 Transportation and Sustainability 82 3.3 Urban Form and Sustainable Travel Relationships: a Review of the Empirical Evidence 96 3.4 Policy Perspectives on Sustainable Urban Travel 125 3.5 Chapter Conclusions 131 4 Methodology for the Spatial Analysis of Intra-Urban Structure and Transport Sustainability 134 4.1 Urban Structure Empirical Analysis Overview 139 4.2 Spatial Data Representation, Analysis and Geographical Information Systems 148 4.3 Urban Geographical Data: Measuring the Socio-Economic City 154 4.4 Urban Geometrical Data: Measuring the Built-Environment 154 4.5 Indicator Datasets Summary, Strengths and Weaknesses 154 4.6 Techniques for the Analysis of Intra-Urban Structure 163 4.7 Techniques for the Analysis of Accessibility and Travel Sustainability 163 4.5 Chapter Conclusions 185 4 5 The Economic Geography and Development of the London Region 187 5.1 London and the South East Region 188 5.2 The Geography of Economic Activity in London 201 5.3 Real-Estate Analysis of Employment Activities in Greater London 225 5.4 Chapter Conclusions 243 6 Accessibility, Journey-to-Work Patterns and Sustainability in the London Region 245 6.1 Mapping Public and Private Transport Accessibility 247 6.2 Overview of Journey-to-Work Patterns in the London Region 256 6.3 Mode-Choice Analysis 266 6.4 Journey-to-Work Travel Distance Analysis 280 6.5 CO₂ Emissions Indicator Analysis 289 6.6 Chapter Conclusions 308 7 Conclusions 311 8 References 325 Appendix A: World Cities Urban Form and Travel Sustainability Dataset 341 Appendix B: London Sectoral Specialisation, 4 Digit SIC 344 Appendix C: Employment Centres Sectoral Specialisation 346 Appendix D: Greater London Real-Estate Analysis 352 Appendix E: Modelling Transport Network Accessibility in the London Region 357 Appendix F: Sub-Regional Journey-to-Work Flows by Mode 367 Appendix G: Journey-to-Work Regression Analyses Tables 369 5 List of Figures 1.1: The Life Cycle of a Technological Revolution 24 1.2: Long Waves of Economic Growth and Technology 24 1.3: Population of Selected US City Municipalities 25 1.4: Intra-urban Transport Eras and Urban Growth 27 1.5: The Expansion of Chicago 27 1.6: The Multi-Nuclei Model 30 1.7: Urban Transport Archetypes 35 1.8: Conceptual Illustration of a Contemporary World City Region 42 2.1: The Four Stage Transportation Model 50 2.2: The Land Use Transportation Feedback Cycle 50 2.3: Model of Urban Land Use and Development 51 2.4: Harvey‟s Circuits of Capital Model 53 2.5: Concentric Land Use Zones Generated by the Bid-Rent Curves 57 2.6: Central Place Hierarchy with Hexagonal Market Areas 59 2.7: The Central Place and Network Models of Urban Structure 66 3.1: The „Three Pillars‟ of Sustainable Development 75 3.2: Integrated Urban Assessment Model 80 3.3: UK Total Travel Distance by Mode 1952-2008 83 3.4: Average Traffic Speeds in English Urban Areas 1999-2006 85 3.5: Final Energy Consumption by Sector 85 3.6: UK Carbon Dioxide Emissions by Sector 2005 86 3.7: UK Transport Carbon Dioxide Emissions by Mode 2005 86 3.8: UK Energy Flow Chart 2007 87 3.9: Carbon Dioxide Emissions by Sector for UK, 1990 to 2007 88 3.10: Estimates of Carbon Dioxide Emissions by Private and Public Transport Modes 89 3.11: Technological Advances Required for Low Carbon Vehicles 91 3.12: Estimated UK Carbon Dioxide emissions from Household Cars by Trip Purpose 93 3.13: Graph of Private Transport Energy Use vs Metropolitan Residential Density 1990 102 3.14: Graph of Private Transport Energy Use / Gross Regional Product, versus Metropolitan Residential Density 1990 104 3.15: Graph of Private Transportation Energy Use Per Capita / Gasoline Purchasing Power versus Metropolitan Residential Density 1990 104 3.16: Graph of Metropolitan Residential Density versus Distance Travelled by Car 106 3.17: Graph of Metropolitan Inner-City Density against Distance Travelled by Car 106 3.18: Graph of Employment Density and Transport Energy Use / GRP 107 3.19: Graph of Employment Centrality and Transport Energy Use / GRP 107 3.20: Graphs of Average Speed by Car versus Transportation Energy/Income Ratio 108 3.21: Graphs of Road Supply versus Transportation Energy/Income Ratio 108 3.22: Graph of Passenger km on Transit versus Transportation Energy/Income Ratio 108 6 3.23: Graph of Transit Supply versus Transportation Energy/Income Ratio 108 3.24: Factors Affecting Urban Transportation Energy Use 109 3.25: Conceptual Models of Urban Spatial Structure and Travel Patterns 120 3.26: Self-Containment Measure for Urban Settlements in the Greater South East 121 3.27: Graph Comparing Average Journey-to-Work Time with Metropolitan Population 126 3.28: Plans for a Transit Orientated City 129 3.29: Transit Infrastructure Plan for Automobile Cities 130 4.1: Aggregation Methods for Varied Scales and Zonations of Urban Spatial Analysis 143 4.2: London Population Map Using Jenks Natural Breaks Classification 145 4.3: London Population Map Using Equal Interval Classification 145 4.3: Ordnance Survey Mastermap Topographic and Address Layer Example 155 4.4: Virtual London 3D City Model with Nitrogen Dioxide Emissions 156 4.5: Virtual London 3D City Model with Querying Building Attributes 156 4.6: Greater London Residential Density at Ward Scale 165 4.7: Greater London Employment Density at Ward Scale 165 4.8: Urban Design Variation at a Fixed Density 166 4.9: Greater London Jobs-Housing Balance 169 4.10: Urban-Centre Hierarchy Patterns, Defined by Spatial Clustering and Centralisation 173 4.11: Estimates of Carbon Dioxide Emissions by Private and Public Transport Modes 182 5.1: Greater London Boroughs 188 5.2: London‟s Historic and Projected Population Graph 189 5.3: London‟s Historic and Projected Population Density Maps 190 5.4: The Evolution of London‟s Public Transportation System 192 5.5: London Road and Motorway Network 193 5.6: Greater London Employment change by broad sectors, 1973-2001 194 5.7: Greater London Index of Multiple Deprivation 195 5.8: London Plan Key Diagram 196 5.9: Opportunity Areas and Indicative Development Capacity 197 5.10: The Greater South East Region and Major Settlements 198 5.11: Growth Areas in the South East Region 200 5.12: Greater London Employment Density and Sub-Regions from 2004 London Plan 205 5.13: South East Employment Density and Sub-Regions 207 5.14: Total Ward Level Employment Change 1991-2001 209 5.15: Total Employment Change District/ Unitary Authority 1998-2004 210 5.16: Workplace Occupational Class Data for City of London and Croydon Town Centre 212 5.17: Occupational Class Indicator, Managerial Employment, for Greater London 213 5.18: Occupational Class Indicator, Professional Employment, for Greater London 213 5.19: Occupational Class Indicator, Managerial Employment, for London OMA 214 5.20: Employment Centre Analysis Results for Greater London and the Wider Region 219 5.21: Employment Centre Specialisation Profile Example 219 5.22: Central London Employment Centre Specialisations 22.