Map of the Month Aug 09 - Time Travel to Major Cities

As Database Coordinator at Collins Geo, I am usually exporting data for the production of published mapping products which are a concise representation of existing geographic features. This map from the World Bank’s World Development Report 2009 caught my eye because it has taken a variety of different data sources and fed them through some clever data analysis software to create a map which shows a different way of looking at our world.


Source: Global Environmental Monitoring Unit, European Commission

The map is essentially one of accessibility as it shows the journey time from the cities of the world, whose population is greater than 50,000 inhabitants, to any other place on Earth. The lightest areas on the map show places that are accessible within one hours travel time of these urban areas, whilst the darkest areas take more than 10 days travel to reach.

In order to create the map, ten different data sources were used in order to calculate a ‘friction’ surface of the world, i.e. a surface that was either easy or difficult to travel across based on factors such as terrain elevation and slope, the need to cross international borders, and the existence of communication routes which in this case included roads, railways, and navigable water routes. Air travel was deliberately excluded from the analysis. Areas of low ‘friction’ included motorway routes which can be quickly travelled along, whilst areas of high ‘friction’ were those of steep terrain where no communication routes exist and only walking from A to B is possible. Throwing all this information together produced the final map.

So what is its purpose? The report explains that “as economies grow from low to high income, production becomes more concentrated spatially. Some places—cities, coastal areas, and connected countries—are favored by producers. ... The way to get both the immediate benefits of concentration of production and the long-term benefits of a convergence in living standards is economic integration.” (WDR 2009, Overview). Using the map in conjunction with other data models such as land cover or population density can help analyse patterns in urbanisation and economic geography such as defining regions where particular economic activities are likely to take place or confirming the links between transport costs and land value.

Overall, the map is a great example of using a variety of data sources to visualise and understand current patterns or trends in our world so that we can better prepare for the future.

Further information about the map can be found from the European Commission’s website at http://bioval.jrc.ec.europa.eu/products/gam/index.htm.

Kenneth Gibson, Database Coordinator, Collins Geo