Building a live online map with your feet on the ground


WIRED:OpenStreetMaps offers the organic result of real-world volunteers plotting their knowledge of local geography, writes DANNY O'BRIEN

IF YOU watched the news in the last month, you’ll recognise the outline in the first few moments of the data visualisation movie: the island of Haiti.

The barest outline of roads and other major features pick out Port-au-Prince and other major towns. As the date indicator crosses the “January 12th” marker, the epicentre of the earthquake appears as bold red circles. Then, minutes later, the first flashes of red and white light up the island’s silhouette. Hour by hour, the island turns from being a general sketch of the nation to an increasingly detailed street map. Within a day, the resolution is similar to an Ordnance Survey Ireland map: streets, paths, rivers are all marked and labelled.

By January 17th, a new set of icons appears: the glowing blue markings of Haiti’s refugee camps, picked out and entered into this map, which is now, after just one week, the most accurate and up-to-date geographical record of Haiti available.

It was constructed, from scratch, by online volunteers at OpenStreetMaps (OSM) and the International Network of Crisis Mappers, analysing and entering data from satellite photographs and aerial photography. It’s still being updated, and still being used by humanitarian efforts in Haiti itself to guide their allocation of resources, their travel routes and evacuation plans.

You can see the visualisation at; to see the map, you just need to visit OSM’s public database at, where the Haiti data sits with an entire globe of mapping information.

At first glance, the site looks like Google Maps, or any of the other mapping services online. Type your local city, town or village, and it’ll take you to a street map of the area. But when you look closer, you’ll see that OSM is more like Wikipedia than another internet map server. There’s a History tab, and an Edit tab. Click on Edit, and (after a straightforward registration process), like Wikipedia, you suddenly find yourself able to change, add or delete anything in your local area. You can flag restaurants or pubs, add a new road or delete a major motorway.

Like Wikipedia, vandalistic deletions are quickly reverted; tiny beneficial additions mount up. Most of OpenStreetMap’s entries in Ireland have been made slowly, street by street, by volunteers painstakingly tracing blurred satellite pictures or walking, driving, and cycling around with GPS devices, then uploading and naming the traces of their path. In the United States, OpenStreetMap has an advantage, because government map data is freely available for anyone to use and re-use. In much of Europe, detailed government mapping data is only licensed at a fee, despite being already paid for by the taxpayer.

In that sense, Ireland’s public map data grows just like Haiti’s, only more slowly. When the crisis in Haiti struck, many of OSM’s volunteers switched from their own local work to tracing out Haiti’s outlines.

Google volunteered its high-resolution satellite imagery, and allowed services like OSM to trace the imagery to form their own maps. Quickly, OSM became, in the words of one OpenStreetMap volunteer working on the ground in Haiti, “the gold standard for base map data in the relief and recovery effort”.

The irony, of course, is that now and going forward, the struggling nation of Haiti will have a better, more usable, more free public database of its own nature than Ireland does. Does that matter? Probably not for traditional businesses, for now. They can pay the money to the Ordnance Survey and trade that off for the commercial benefit of reusing that data. But as Ireland slowly catches up with Haiti, other business models will develop that could only exist with free map data.

OpenStreetMap’s licence will soon mean that users who make their adapted version of the map have to contribute their changes back to the community. It also requires that you can’t use technological measures to restrict how people use your distribution of the map data. That means no locked-up, unalterable versions of the map will be legal.

There are exciting applications that can be developed using this model. One spin-off group is working to create OpenSeaMap, which would provide free nautical maps, including details of buoys, submerged dangers and sea routes.

Out-of-date and expensive maps of the sea are a perennial problem among maritime navigators: OSM may change that by encouraging sailors to contribute their own changes in return for free access. Another is working on routing: the “satnav” capability that lets GPS systems in cars find the directions from one place to another. Instead of paying for expensive updates, drivers could download free information – and correct dumb mistakes instead of just railing at the idiocy of the talking satnav announcer.

But what it also means is that those old business models that depend on paying more to the Ordnance Survey will have a new set of competitors. As will the Ordnance Survey. One hopes they’ll see it as much an opportunity as did the aid workers in Haiti – and not a disaster that they must do everything to prevent.