What these data are and what they are not
Accessibility maps are made for a specific purpose and they cannot be used as a generic dataset to represent “the” accessibility for a given study area. The data described and presented here were used to create an urban/rural population gradient around large cities of 50,000 or more people. The assumptions made in the generation of this accessibility map can be found in the description and data sources links on the left. If these assumptions sound reasonable for your requirements then the data are available for download. If, however, the assumptions do not match your requirements then you can use the information in these pages as well as the software and external links to create your own accessibility model.
À partir des travaux de Uchida, H. and Nelson, A. #Agglomeration_Index : Towards a New Measure of Urban Concentration. Background paper for the World Bank’s World Development Report 2009.