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Vizzuality Blog

The Global Map of Accessibility.

Global map of access to cities published by Nature.

The journey of life.

Education, healthcare and financial opportunities are just a few of the building blocks of a good life. Understanding how far people have to travel to access these services can help us prioritise which areas of the world need development assistance. Until now, this information could only be accessed using datasets or a static map image created in 2008. But now, with the launch of the new Global Map of Accessibility, you can view the travel time between almost any point on Earth and the nearest city in a matter of seconds.

The map draws on a study published this week in Nature. Our teammate Simão Belchior is named as an author on the paper for his role in leading Vizzuality’s contribution to the study. The study reports that 80% of the global population lives within one hour of a city. However, there’s a disparity between high-income countries, where 90.7% of individuals live within an hour of a city, and low-income countries where that figure drops to 50.9%.

Working with the University of Oxford’s Malaria Atlas Project, the Joint Research Centre of the EU, Google, and the University of Twente, we designed and developed an interactive global map of access to cities. Using this map, anyone can view the travel time between almost any point on Earth and the nearest population centre of 50,000 or more people. In addition to predicting access to services, the map and associated database can also be used to identify where the world’s wild places remain untouched by humans.

“Two roads datasets underpin this work — OpenStreetMap and derivatives from the Google roads datasets — and by combining these sources we have something quite unprecedented in its level of detail and precision,” said the paper’s lead author, Dr Daniel Weiss, University of Oxford. “Major improvements in available data have occurred since the previous global accessibility map was made, so we considered this an opportunity to improve our work on infectious disease modelling and mapping as well as make a useful dataset for others.”

We’ve come a long way.

The predecessor of this new map was published almost 10 years ago. What started as a static image has now evolved into a beautiful, interactive map.

The 2008 version of the Global Map of Accessibility
Today’s interactive map allows you to zoom in and view the travel time between almost any point on Earth and the nearest city.

“We’ve made huge technological advancements since 2008,” said David González, Vizzuality’s founder and Chief Technology Officer. “We have more information than ever before from satellites, and crowdsourcing via projects like OpenStreetMap has allowed us to tap into our ‘collective intelligence’. Cloud computing and big data allow us to process all this data in greater resolution and put it at the fingertips of anyone who wants to use.”

Mapping accessibility data allows us to understand a number of factors associated with human wellbeing and development, such as the likelihood that people will seek medical care when they are ill, or what level of education they are likely to attain. It can also help us predict food security and inform decisions that contribute to the worldwide effort to eliminate malaria.

For example, the University of Oxford uses access to cities as a variable in its estimates of the impact of malaria on national economies, mortality and morbidity. This information, together with maps of the spatial distribution of malaria, is relied upon by the World Health Organisation and other institutions to identify areas where bed nets and antimalarial drugs need to be distributed.

“Design too has had an important role in the evolution of data visualisations since the original accessibility map was created,” said Sergio Estella, Vizzuality’s founder and Chief Design Officer. “Infographics are now interactive and users can customise what they see. Design helps people do this by making information more digestible and prioritising the data that will draw users in. Cartography is more accessible than ever before and you no longer need to be GIS specialist or software engineer to access tools that help you visualise data in engaging ways.”

Developments in design and technology have helped us put unmapped places on the map. Roads that were ‘missing’ from the 2008 map are now included, which means the people who use them are also accounted for. Advances in satellite technology and data processing means we can spot roads as they appear, and monitor deforestation, in almost real-time.

With each improvement we make to the collection, analysis and visualisation of data, we open up new opportunities to use our resources more efficiently. This map of global access to cities could help us ensure economic development balances the environmental costs it often occurs, and help direct us to a future that is equitable for all.

Explore the map for yourself here.



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