How long does it take to get from A to B and what is the 'cost' of doing so? In a recent paper in the Nature journal Scientific Data, Andy Nelson (Professor of Spatial Agriculture and Food Security at ITC, University of Twente) and colleagues document nine new global and spatially detailed datasets that map travel time to the opportunities, resources and services that are typically concentrated in urban areas. The paper also provides a first spatial validation of the underlying global models and demonstrates that the travel time estimates are plausible and useful in many geographies.
Access to food, water, education, health services and employment opportunities are all related to people's well-being and their ability to be economically active. Accessibility is simply a precondition for many basic needs. But who has access and who does not? Andy Nelson and colleagues answer this question with nine new global and spatially detailed datasets. Professor Nelson states: “The dataset improves upon existing information by recognising that city size does matter in terms of the resources and services they provide. There is a need to measure the physical access to cities of different sizes, something that had not been explicitly looked at before globally.”
Estimating physical access to resources
This work is part of ongoing research to estimate physical access to resources, to identify where inequalities in access exist, where there are opportunities to improve access and to assess the resulting benefits. As the paper notes “Inequalities in access can lead to greater social and economic divides. Poorly planned expansions of transport networks can also degrade the natural environment, leading to deforestation and the overexploitation of easily accessed natural resources. On the other hand, well-planned improvements in access can lead to better outcomes in rural health, wealth and economic livelihoods whilst limiting environmental impacts.”
The research is a contribution to develop a broader range of global accessibility indicators for the year 2015 to represent access to the different resources, services and opportunities that are available in settlements of different population sizes. The research, methods, data and code were published as Open Access resources. “We hope to see further uptake and development of these models of accessibility in the context of sustainable development”, says professor Nelson.
Applications related to sustainable development
These new spatial layers of global information on travel time are already being used for research and education related to sustainable development. One team are using the data to estimate food/nutrition losses and transport costs between farms and cities, while another is looking at the evolving relationship between rural and urban areas, and economic development in the 21st century. At ITC the travel time models have been used in MSc programmes and short courses to look travel time to health care facilities and the loss of accessibility due to natural disasters.
The dataset was developed by Andy Nelson at ITC in collaboration with Andrea Cattaneo and Theresa McMenomy from the Food and Agriculture Organization of the United Nations, Dan Weiss from the University of Oxford, Jacob van Etten from Bioversity International and Jawoo Koo from the International Food Policy Research Institute. It was supported by a grant from the CGIAR Platform for Big Data in Agriculture - CSI Mini-Grants for Open Geospatial Datasets. The research is published as Open Access and can be found here: