A Web-based Accessibility Analysis Service Using OpenStreetMap Data

In recent years, the rapid development in GPS and Web2.0 technologies has profound impacts on geographic information creation, assembling and dissemination. A brand-new data acquisition method has been ermerging as the widespread engagement of large numbers of private citizens, often with little in the way of formal qualifications, in the creation of geographic information. Massive geographical data have constantly been created and updated, and the time for geographic information access and dissemination is thus significantly reduced. Michael Goodchild termed this phenomenon as Volunteered Geographic Information (VGI). Among many formats of VGI, OpenStreetMap (OSM) is intended to create a world map using free data from GPS units, aerial photography and other sources. Because of its free access and quick update, OSM has been been employed to carry out innovative studies by researchers and academic institutionsThis thesis adopts OSM data to develop a web-based accessibility analysis and service for the general public. We extract and process street and public transport data of the entire Europe with over dozens of gigabytes of data. Huge graphs are generated through data-intensive computing both for the street network and the public transport network. Based on the massive preprocessing, we can make appropriate queries such as isochrones, public transit, stops and points of interest. The contributions of the thesis include (1) applications of VGI in general and OSM in particular for geographic information services or location based services, (2) data intensive geospatial computing based on free VGI, and (3) extension of accessibility analysis into the location based services for the general public.