We estimate that over one billion people do not have sufficient access to a road. This figure comes with a string of caveats, but it can help move the conversation forward on the Rural Access Indicator (RAI), one of the most important global development indicators in the transportation sector. What is the RAI and why should you care? The Rural Access Indicator (RAI) is the proportion of the rural population who live within two kilometers of an all-season road. It provides a measure of transport connectivity. Transport connectivity provides a measure of access to vital services; educational, economic, health, etc. The RAI is synonymous with the Sustainable Development Goal (SDG) indicator 9.1.1. In many developing countries, most farmers are disconnected from local, regional, and global markets. This lack of access can perpetuate cycles of poverty. Improved understanding of where infrastructure is deficient can help prioritize investments to connect people through sustainable and resilient infrastructure to support economic development and human well-being. How did we measure the RAI globally? Two key pieces of information are required to calculate the RAI: roads and population. We need to know the location and quality of roads and we need to know where people live and whether they are rural or urban dwellers. Three open datasets provide a useful starting point for this data; OpenStreetMap for road data, WorldPop for population data, and the Global Urban-Rural Mapping Project (GRUMP) for urban/rural classification. These datasets are admittedly incomplete. But they are the best, global datasets available to calculate the RAI for every country using a consistent methodology. This is a lot of data. WorldPop data is available in a raster format at 100-meter pixel resolution for every country. The team at WorldPop divides the entire world into a grid of cells, each 100 meters on a side, and for every cell estimates the number of humans living there. They use satellite imagery, census data, and a host of other datasets. Learn more about their methodology at https://www.worldpop.org/methods. OpenStreetMap is a collaborative, editable map of the world. In many locations it is the best available map. People can tag roads with attributes like surface type and road category. In partnership with UKAID and ReCAP, Azavea used open source geospatial processing tools, notably, GeoTrellis (geotrellis.io) to run the calculation for the RAI for every country globally. This talk will cover: SDGs, RAI, GeoTrellis, and global geospatial processing tools.
