'Citizen cartographers' map the microcosms of the world

By Mike Musgrove
Washington Post Staff Writer
Sunday, January 31, 2010; G01

On a cold Sunday morning in Washington, none of the two-dozen scruffy students and techie folks crowded into one side of a bustling cafe noticed as Steve Coast, a 29-year-old British programmer, moseyed in and joined their ranks. They didn't realize it, but there was the man with a plan to map the world.

They were there to do their part, but that's the funny thing about being the leader of a large, online movement: Everybody knows your name, but nobody recognizes you.

The citizen cartographers, known as MappingDC, had gathered to help complete Coast's interactive map of the globe -- or at least Washington's corner of it.

"Maps are expensive and proprietary," said Coast, sipping on his coffee and explaining the core tenets of the project, called OpenStreetMap. "They should be free."

Coast had the idea for OpenStreetMap in 2004, when he was a student living in London. Coast had a GPS and a laptop, you see, and he figured that with a little programming magic he could build a map of his local haunts that contained more useful information than any service he could find online.

What's more, he said, "I figured that if I did that, and he did that, and you did that, then, together, we could put together a jigsaw map of the world."

Since that day, a few hundred thousand people around the planet have pitched in online to enter information about everything from the name of their local library to an area's handicap accessibility.

In Germany, the country with some of the project's most enthusiastic participants, volunteers have very nearly catalogued their country down to the last lamppost. During a recent trip to Atlanta, Coast found that users had paid particular attention to the area's storm drains, perhaps because of recent floods. In Denver, where he lives, Coast has noticed that users are obsessed with noting every footpath and bike trail.

As with Wikipedia, the premise here is that the collective contributions of an enthusiastic community can create a better service than something a corporate entity could put out on its own.

Sure, Google, with its massive resources, has the wherewithal to hire workers to record the street-level images used in its map service. But "a couple of guys driving a truck down a street don't viscerally care" about whether they captured your neighborhood's streets exactly right, said Coast, who was in town to attend a conference by the U.S. Geological Survey.

Remember encyclopedias? The problem with those dead-tree tomes was always that the information printed within could go obsolete the day they were published. It's always been the same for paper street maps, too. MappingDC and OpenStreetMap project members argue that their map is better because it can be instantly corrected. Again, like Wikipedia, the belief is that the wisdom of the crowd will prevail or fix errors.

Anyone with the technical skill can download information to contribute to the OpenStreetMap project. A handful of map services available at Apple's App Store use the project's data, including OpenMaps, OffMaps and MapTap.

MappingDC, formed last summer, holds such "mapping parties" on a semi-regular basis; previous events have been thrown in Bethesda and Silver Spring.

Serge Wroclawski, one of the local group's leaders, admitted that the outings aren't absolutely necessary, since anybody with a computer connection and a few skills can contribute to OpenStreepMap on their own. But such events are a decent excuse for the project's enthusiasts to get together, and maybe spread the word.

It was also, on that Sunday, an opportunity to confuse the locals.

After the morning meet-up, where members and guests divvied up the areas they would be covering, MappingDC participants hit the streets for hours. A woman stopped and watched as Chris Covington snapped a picture of a bike rack outside the Federal Triangle Metro station and his friend Wade Duvall made a note on a printout of the area.

Washingtonians are used to seeing camera-wielding tourists snapping away at the sights -- but bike racks and park benches?

Later, Covington and Duvall spent hours sorting out the dozens of snapshots parked on his GPS-enabled smartphone and uploaded the bounty from the morning's expedition. And instantly, Washington's map was a little more complete.

"It's about making a better map than Google," Covington said. "It's about making the best map possible."

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