Spatial optimization for land use allocation: accounting for sustainability concerns

Land-use allocation has long been an important area of research in regional science. Land-use patterns are fundamental to the functions of the biosphere, creating interactions that have substantial impacts on the environment. The spatial arrangement of land uses therefore has implications for activity and travel within a region. Balancing development, economic growth, social interaction, and the protection of the natural environment is at the heart of long-term sustainability. Since land-use patterns are spatially explicit in nature, planning and management necessarily must integrate geographical information system and spatial optimization in meaningful ways if efficiency goals and objectives are to be achieved. This article reviews spatial optimization approaches that have been relied upon to support land-use planning. Characteristics of sustainable land use, particularly compactness, contiguity, and compatibility, are discussed and how spatial optimization techniques have addressed these characteristics are detailed. In particular, objectives and constraints in spatial optimization approaches are examined

Scale-Free Phenomena in Communication Networks: A Cross-Atlantic Comparison

?Small-world networks? have a high degree of local clustering or cliqueness, like a regular lattice and a relatively short average minimum path, like a completely random network. The huge appeal of ?small-world networks? lies in the impact they are said to have on dynamical systems. In a transportation network, ?small-world? topology could improve the flow of people or goods through the network, which has important implications for the design of such networks. Preliminary research has shown that ?small-world network? phenomenon can arise in traffic networks possessing ?small-world? network topology (i.e., in a network that has a structure somewhere in between a regular lattice and random graph) and that, at least under certain circumstances, traffic appears to flow more efficiently through a network with such topology (Schintler and Kulkarni, 2000). This paper will explore this further through simulation under varying assumptions regarding the size of the network (i.e., in terms of number of nodes and edges), the level of traffic in the network, the uniformity of nodes and edges and the information levels of travelers in the network. The simulations will be done using the random rewiring process introduced by Watts and Strogatz (1998), where each time the network is rewired, the distribution of traffic and congestion through the network, and the ?small-world? network parameters, shortest average minimum path and clustering coefficient, will be examined. Traffic flow will be estimated using a gravity model framework and a route choice optimization program. The simulations will also be used to reveal whether or not there are certain nodes or links that suffer at the expense of the entire network becoming more efficient. In addition, the possibility of a self-organised criticality (SOC) structure will be examined. The concept, introduced by Bak et al.,(1987), gained a great deal of attention in past decades for its capability to explore the significant and structural transformation of a dynamic system. SOC sets out how prominent exogenous forces together with strong localized interactions at the micro level lead a system to a critical state at the macro-level. A further step in our analysis is the investigation of whether a power-law distribution, characteristic of the SOC state, evolves in the traffic network. While ?small-world? network topology may be shown to improve the efficiency of traffic flow through a network, it should be recognized that ?small-world? networks are sparse by nature. The shut down or major disruption of any link in such a network, particularly one with heavy congestion, could provoke significant disorder. This paper will also explore the effect that disruptions of this nature have on networks designed with a high degree of local clustering and a short average minimum path. The fact that a ?small-world? network is sparse also raises other issues for the transportation planner. If ?small-world? topology is in fact a desirable property for transportation networks, how do we transform existing networks to produce these results? Unlike other networks, such as those for telecommunications or socialization, a transportation network cannot be rewired to achieve a more efficient network structure. This issue will also be addressed in the paper. REFERENCES Bak, P., C. Tang, and K. Wiesenfeld (1987), ?Self-Organised Criticality?, Physical Review Letters, Vol. 59 (4), pp. 381-384. Watts, D.J. and S.H. Strogatz (1998). ?Collective Dynamics of ?Small-World? Networks? Nature, Vol 393, 4, pp. 440-442. Schintler, L.A. and R. Kulkarni (2000). ?The Emergence of Small-World Phenonmenon in Urban Transportation Networks? in Reggiani, A. (ed.), Spatial Economic Science: New Frontiers in Theory and Methodology, Springer-Verlag, Berlin-NewYork, pp. 419-434.

The Dynamics of Growth and Distribution in a Spatially Heterogeneous World

This paper tries to reconcile growth and geographical economics by dealing directly with capital accumulation through time and space and by seeing growth convergence and spatial agglomeration as jointly generated by dynamic processes displaying pattern formation. It presents a centralized economy in which a Bergson-Samuelson- Millian central planner finds a flow of optimal distributions of consumption, subject to a spatial-temporal capital accumulation budget constraint. The main conclusions are: first, if the behavioral parameters are symmetric, but there is an asymmetric distribution of the capital stock, then the long run asymptotic distribution will be spatially homogeneous; second, if there is homogeneous distribution of the capital stock, but there is an asymmetric shock in any parameter, then the economy will converge towards a spatially heterogeneous asymptotic state; third, spatially heterogeneous asymptotic states will only emerge exogenously, not endogenously; fourth, the spatial propagation mechanism can give birth, when the production function is close to linear, to a Turing instability, which implies that for some parameter values, a conditionally stable spacetime distribution should display spatial pattern formation.Optimal growth and distribution; Spatial growth; Optimal control of partial differential equations; Traveling waves; Fourier transforms; Turing instability.

17-06 Public vs Private Transportation Network Accessibility and Maternal-Infant Health Outcomes Across the Urban-Rural Boundary in Kalamazoo County, Michigan

This project is twofold. The first part of the project deals specifically with the benefits of multimodal transportation modeling to understand community structure of public health access in a community. Maternal risk and infant outcomes are examined in Kalamazoo County, MI with respect to transportation network accessibility by public transit and private vehicle across the urban-rural continuum. Infants born to mothers just outside the urban core had a higher rate of poor outcomes. Maternal risk factors, by contrast, were associated with the accessible rural areas – areas outside the city proper, but within 30 minutes by car to services. When as much variability as possible (departure time, routes, modes, time of day) was included in the model, very detailed community structure information emerged. This structural information is not specifically causal, but differences in behaviors and use of services, as well as differences in urban poverty and rural poverty were apparent. The second part of the project considered raster-based methods to provide insights into siting intervention locations at efficient and equitable locations for repeating cases of risk – in this case, repeating cases of sexually transmitted infections. The results provide metrics for decision makers to compare intervention locations by efficiency and equity across multimodal optimization

The relationship between municipal highway expenditures and sociodemographic status: Are safety investments equitably distributed?

Different population groups have varying transportation needs based on their region type, socio‐economic, and socio‐demographic characteristics. Yet, municipal highway funding allocation methods do not typically consider these differences. Throughout the United States, municipal highway funding allocation is based upon fixed formulas that often only account for highway mileage and/or population size rather than equal benefits and funding outcomes across different population groups. This potentially creates an inequitable funding allocation process leading to safety and accessibility disparities between different population groups. This research investigates the extent to which the distribution of resources is not equal when evaluated by population group. Specifically, the relationship between municipal highway expenditures and poverty levels, population aged 65 years and older, race, and remoteness is investigated using data from the states of New York and Massachusetts. Using linear regression techniques, several models were developed that relate municipal highway expenditures with the socio‐economic and socio‐demographic characteristics of municipalities. The results revealed that there are clear municipal highway expenditure disparities between different population groups. Municipalities that have higher poverty levels experience a lower highway expenditure rate per local mile. Further, municipalities located in remote areas far from large metropolitan regions experience a disproportionately lower highway expenditure rate per local mile. Moreover, the results of this study indicate the need to consider how funding methods can address social differences