Researchers studying the crowdsourced mapping database OpenStreetMap have concluded that it currently sits at about 83 per cent complete, making it the world’s only reliable openly licensed source for global geospatial road data.
OpenStreetMap, the “Wikipedia of maps,” started in 2004 as a collaborative, volunteer-edited source for geographic information. Now boasting over 3.8 million contributors and a database of about 411 million roads, coastlines, administrative boundaries and other features, the project has spread rapidly throughout the world, moving from an initial focus on streets and roads to the mapping of buildings, land uses and points of interest. It’s also had a name change, to OpenStreetCam.
Last year, the company launched OpenStreetView, giving contributors the power to upload images to create a large-scale photo database to compliment its maps. And yes, the parallels to Google Maps and Google Street View are clear, thus begging the question, why does the world need OpenStreetMap (OSM) when one of the world’s largest tech companies already has it covered?
“Google Maps and similar proprietary products do not permit geospatial analyses such as calculating road lengths,” say the study’s authors, from McGill University in Montreal and University of California, Santa Cruz, California. “Even basic cross-national data on the length of roads are lacking.”
“Why do we need a project like OpenStreetMap?” asks Serge Wroclawski, a long-time contributor to OSM, in a 2014 blog post. “The answer is simply that as a society, no one company should have a monopoly on place. Place is a shared resource, and when you give all that power to a single entity, you are giving them the power not only to tell you about your location, but to shape it.”
As well, the comparison to Google Maps is said to be a little off-centre, as OSM is less oriented at the individual consumer and more focused on aiding other organizations, from bike companies to municipalities to health organizations, in creating their own maps using OSM’s data.
But OpenStreetMap’s value hinges on the quality of its data and, crucially, on how completely it covers a given area, say the new study’s authors, hence the need to assess OSM at a global level. “The absence of a global completeness assessment, meanwhile, hampers the use of OSM for research in economics, urban planning, environmental studies and related fields, such as analyses of worldwide patterns of travel behaviour or urban development,” say the authors.
To that end, researchers compared OpenStreetMap’s data with aerial imagery and created a computer model to assess the growth of OSM’s street network, finding that, overall, the world’s road network is about 83 per cent completely mapped by OSM. For about 42 per cent of the world’s countries, OSM is more than 95 per cent complete (high enough to be used in scientific research and analysis) while in others the database is less comprehensive but rapidly growing.
The researchers found that both highly-dense regions like cities as well as the more sparsely populated areas turned out to be more completely mapped. Surprisingly, the findings show that a country’s GDP did not figure strongly into determining its how completely it was covered by OSM. Instead, countries with high levels of governance and good internet access (for access to satellite imagery, for example) turned out to be better mapped.
“The open governance indicator may relate to the availability of geographic data, and even the ability of private citizens to undertake mapping efforts. China, for example, restricts private surveying and the publication of geospatial information,” say the authors, whose research is published in the journal Plos One.
This year, OpenStreetMap is holding its annual “State of the Map” conference in Aizuwakamatsu, Japan.