How long does it take to get from Pike Place Market to Mount Rainier National Park? According to Google Maps, it’s a 5 minute walk; less than 1/3 of a mile. Pretty easy, huh?
Mount Rainier looks an awful lot like an office tower to me. That'll be one steep climb!
In reality it’s a 2 1/2 hour drive.
This error is the result of a fundamental challenge in how data is collected for online navigation and local search products: all of the major services use data that weren’t originally collected for navigation. The typical source is phone books listings, which were originally compiled by companies like InfoUSA to sell mailing lists. In this particular case, the national park likely has a business office in Downtown Seattle.
The data have a distinct bias: toward places with phone numbers. While you can get exact driving directions to a local ball bearing distributor, look for a park, landmark or trailhead and you’ll often get erroneous data or no results at all. Occasionally, you’ll luck out and there will be business names nearby that incorporate the place name.
Just for fun, try finding the Albert Einstein statue in Washington, DC using an online mapping service. (If you can’t find it, click on the image to see the answer.)
On Sunday, I was looking for Hippie Hill in Golden Gate Park. Yahoo! Maps struck out entirely. Mapquest delivered a bunch of unrelated results.
An answer lies in another Yahoo! property: flickr’s database of geotagged photos. Although flickr’s search tools aren’t optimized for local search, it’s content is a great data source. The first search result in Google Maps for Hippie Hill is spot on; it came from Google indexing flickr’s geodata. The commercial results on the same map (the red markers) are mostly garbage.
Flickr is just one tool. As more people adopt GPS-enabled phones like the iPhone, we’ll see more and more user generated data. Enabling mobile data collection is reason enough to build an iPhone app.
Developing countries have the potential to leapfrog the developed world in data quality. Google’s Map Maker allows anyone to populate data in countries without large commercial data providers. You can pull up a satellite view and trace roads. Zoom into buildings and add local businesses. Find a park and add in key features. Because the content is user generated, the places that people look for the most will be added first, as opposed to the local ball bearing distributor. Places with colloquial names will become findable.
User-generated content has its challenges, of course. In the initial stages, tools like Map Maker will attract the community organizers who are passionate about their neighborhoods. Once the data start getting even modest usage, spammers will attack. But many of the standard spam fighting techniques can be used to deter them.
OpenStreetMap and Wikimapia offer similar functionality. OpenStreetMap is focused on creating and editing roads; Wikimapia is focused on places of interest.
Google Map Maker’s user interface is more intuitive than OpenStreetMap and Wikimapia. Unfortunately, Google is being hypocritical in how it treats the data. While Google Maps combines data from other sources, such as indexing geodata from flickr, it is keeping content generated by Map Maker users locked up. Users can’t even download the data they create.
More on: geotagging, local search, maps
Rakesh Agrawal's blog 
