Netw Spat Econ (2007) 7:297–300 DOI 10.1007/s11067-007-9033-8
Transport Networks and Metropolitan Development: New Analytical Departures Guest Editorial: Towards a Network of Simplicity Aura Reggiani & Peter Nijkamp
Published online: 29 August 2007 # Springer Science + Business Media, LLC 2007
A key feature of the modern space-economy is the transition to a networked society, where interconnectivity and interoperability between the different economic systems play a significant role (Reggiani and Schintler 2005). Consequently, there is a consensus among scientists on the idea that many spatial economic phenomena can be described by a network of interactions among agents (Friesz 2007; Reggiani and Nijkamp 2006). Surprisingly, even though the application fields are quite different and the networks are space–time complex, these networks often show common behaviour, based on their topological characteristics. In other words, the topological properties of a network can give useful insights on how the network is structured, which are the most “important” nodes/agents, and how network topology can influence the conventional spatial economic laws (such as, equilibrium theory, spatial interaction theory, etc.). In sum: “the topology (or architecture) of the interaction is an essential part of many processes and it cannot be ignored without missing a crucial ingredient of the phenomena at hand” (Vega Redondo 2006). Such network embedding is important, for example, to understand how transportation networks are resilient, or how commuting flows and employment are related in modern labour markets, or how hierarchical land use patterns develop over time. Interestingly, the analytical tools developed in this context seem to be quite ‘simple’, mostly devoted to searching for and extrapolating some ‘order’ principles in the complex networks under analysis. In addition, they seem to revisit—in a network framework—the main laws of spatial economics developed in the 1960s– 1970s (e.g. the spatial interaction-entropy models conceived of by Wilson 1967). For example, if we find—in certain complex network typologies—the well-known A. Reggiani (*) Department of Economics, Faculty of Statistics, University of Bologna, Piazza Scaravilli, 2, 40126 Bologna, Italy e-mail:
[email protected] P. Nijkamp Department of Spatial Economics, VU University Amsterdam, De Boelelaan 1105, 1081 HV Amsterdam, The Netherlands e-mail:
[email protected]
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Albert and Barabási (1999) power law model, we may infer a rank-size rule of the Zipf (1949) type expressing hierarchical nodes, or if we calculate the redundancy of a node, in order to test the “structural” holes (Burt 1992) in a network, we end up with a function strictly related to the entropy concept—concerning spatial economic systems—developed by Wilson in the 1970s. That is the conceptual background of this Special Issue. The volume intends, first, to provide, by means of six contributions, new analytical insights into the modelling and analysis of (complex) transportation networks—in the light of their impact at a metropolitan/urban scale—utilizing perspectives from North America and Europe; second, these six works also constitute a methodological platform from where we want to explore whether, among the different network approaches discussed here, a unifying conceptual framework can be identified.
Graph Theoretic Approach to Model Transport Network Resiliency
Traffic Grammar/ Algorithmic Entropy for Measuring Randomness/Order in Traffic
Network Connectivity and Centrality
Power Law and Entropy Models for Identifying Spatial Clusters in Commuting
Network Variety/Order and Dispersal
TRANSPORT NETWORKS AND METROPOLITAN DEVELOPMENT: NEW ANALYTICAL DEPARTURES
Meta
Geosimulation and Entropy to Model Land Use Changes
GIS Activity Space Analysis for Modelling Accessibility in Social Networks
Meta-analysis for the Value of Travel Time Savings in Passenger Transport
Value Transfer
Fig. 1 Structure of the methodological directions of, and linkages among, the papers in this Special issue
Transport Networks and Metropolitan Development: New Analytical Departures
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The idea of this Special Issue originates from STELLA (Sustainable Transport in Europe and Links and Liaisons with America), a European network of scientists dedicated to fostering Transatlantic transportation research. Its North American partners came from the STAR network (Sustainable Transportation Analysis and Research) supported by the National Science Foundation. The findings and new directions emerging from the STELLA-STAR Project1 have also been the focus of three Special STELLA-STAR Sessions2 organized in Las Palmas, Spain, in June 2005, in the framework of the Euro-NECTAR3 (Network for European Communication and Transport Activities Research) Conference. In this framework, the editors wish to thank Piet Rietveld (Chairman of NECTAR) for his dedicated cooperation, as well as Juan Carlos Martín (Faculty of Economics, University of Las Palmas) and his staff for their great scientific input and organizational support. This particular Special Session aimed—as mentioned—to highlight recent advances in analyzing and modelling the dynamics of a modern spatial network society. In this methodological perspective, we can link the six papers as illustrated in Fig. 1. It is clear that all the methodologies developed in the six papers have a fundamental element in common: the search for hidden order or regularity, which can enable the complexity of the network concerned to be ‘decoded’. In particular, we may single out the following tools: (1) measures of network connectivity and centrality in the first two papers (the first by Laurie Schintler et al., with reference to Washington D.C.’s arterial network, and the second by Roberto Patuelli et al., with reference to the commuting network in Germany); (2) measures of network variety/order/dispersal in the subsequent two papers (the first by Kingsley Haynes et al., with reference to the urban freeway traffic network, and the second by Heng Sun et al., relating to the transportation network, land use, and urban sprawl in the city of Calgary); (3) measures of values transfer in the final two papers (the first by Luca Zamparini and Aura Reggiani on the estimation of travel time savings with reference to a meta-analysis of 53 international studies on passenger transport, and the second by Talia McCray and Nicole Brais on the spatio-temporal travel activities of low income people in Quebec City). Overall, this Special Issue—by means of the various contributions—aims to provide an overview of the recent analytical and methodological directions in transport analysis with respect to the development of the related spatial and network patterns, and their interactions with various economic activities. All contributions have been refereed. The editors are grateful to all the authors and referees for their valuable and careful collaboration, by providing new insights into, and reflections on, the field.
1
http://www.stellaproject.org
2
Two further Special Issues emerged from the other two STELLA-STAR Special Sessions (see Black et al. 2006; Zamparini 2007).
3
http://www.nectarist.free.fr
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A final observation concerns the general ‘lesson’ emerging from the papers considered here, i.e. the need for the social sciences—especially the spatial and economic sciences—to highlight some implications of modern complexity/network theory for spatial economic analysis, by providing tentative pathways for alternative research lines. The emerging unifying search of ‘hidden’ order and hence, of spatial network ‘simplicity,’ is undoubtedly an interesting methodological issue worthy of deeper consideration. It is hoped that this Special Issue constitutes a platform from which further research challenges and endeavours can be launched, in particular concerning the main questions on how we can relate network to equilibrium structure and how network structures affect interacting economic activities.
References Albert R, Barabási AL (1999) Emergence of scaling in random networks. Science 286:509–512 Black B, Nijkamp P, Reggiani A (2006) Special issue on: towards new transatlantic transport research: the STELLA-STAR project on the move. EJTIR 6:1 Burt R (1992) The structural holes: the social structure of competition. Harvard University Press, Cambridge, MA Friesz T (ed) (2007) Network science, nonlinear science and infrastructure systems. Springer, New York Reggiani A, Nijkamp P (eds) (2006) Spatial dynamics, networks and modelling. Edward Elgar, Chelthenam, Glos Reggiani A, Schintler L (eds) (2005) Methods and models in transport and telecommunications: cross atlantic perspectives. Springer, Berlin Vega Redondo F (2006) Complex social networks, http://merlin.fae.ua.es/fvega/outline-research.htm Wilson A (1967) A statistical theory for spatial distribution models. Transp Res 1:253–269 Zamparini L (ed) (2007) Special issue on: logistics, networks and sustainability in freight transport. EJTIR 7:2 Zipf GK (1949) Human behaviour and the principle of least effort. Addison-Westley, Cambridge, MA
