Analysing spatial accessibility patterns with travel time and distance measures: novel approaches for rural and urban contexts
Year: 2014
Type: dissertation
Abstract: Accessibility plays a key role in shaping the patterns of human activity on all spatial scales. Accessibility questions are particularly topical now that cities around the word strive for more sustainable urban mobility and information on human influence on natural systems is needed in order to better understand processes of global environmental change. Following these lines of development, supporting different spatial planning processes with quantitative accessibility information has become increasingly important, and different accessibility analysis methods are actively being developed for this purpose. Furthermore, availability of new types of data and increasing computational power enable novel approaches and a level of detail in analysis that were unfeasible in the past. This thesis addresses accessibility questions through five case studies in two different contexts. Two case studies take place in the rural Peruvian Amazonia (Loreto region) where the extensive river network forms the backbone of regional transportation and people s daily mobility. The other three case studies are conducted in the capital region in Finland (Greater Helsinki), and the focus of these studies is on urban environments. The contribution of my work is both methodological and contextual; I aim at finding novel data sources for spatial accessibility analyses and further developing methods for quantifying accessibility as distances and travel times. On the other hand, I aim at (visually) describing and understanding the spatial patterns of accessibility in my study areas and at analysing and discussing the implications of accessibility for the spatial organisation of land-use and people s daily mobility. My results show that realistic accessibility analyses require a consideration of different travel modes and regionally specific transport network properties. In fluvial transport networks, travel time analysis is particularly sensitive to river channel types, direction of movement and seasonality. In urban settings the door-to-door approach for multimodal travel time calculations gives more realistic results than in-vehicle travel time only, and it also makes the different travel modes mutually comparable. The value of the more advanced quantification methods becomes particularly visible when the results obtained from the accessibility calculations are further applied in new analyses. The use of simple Euclidean distances may, however, be justified in situations where appropriate data for more advanced analysis is lacking, but knowing the limitations and simplifying assumptions of these measures is important when applying them. The key contextual findings of this thesis are based on quantitative descriptions and visualisations of the spatial patterns of accessibility in the case study areas. Quantitative data on accessibility also serve as an input for analyses of human livelihoods (such as modelling of potential production zones for different agricultural produce in Loreto) and land-use pressure (such as Amazonian deforestation modelling). My results furthermore show how accessibility to services and other daily activities is an important factor influencing urban residents travel behaviour and its environmental sustainability in Greater Helsinki. Finally, this thesis provides examples of how different types of data sources and their innovative combinations can be used in accessibility analyses. In the case studies I utilize and thus also introduce freely available computational tools for detailed multimodal travel time analysis.
Source: Työväentutkimus Vuosikirja
Author: Maria Salonen
Language: English
Subfield: Transportation
Field: Social Sciences
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W1557043012