Google Map Maker, the crowdsourced mapping Web app launched in 2008 and available in 183 countries, is finally coming to the United States. It's an important addition to Google's mapping services here and could make for maps that are vastly more detailed and useful than they are currently.

In some countries (like Romania, Tech Lead Lalitesh Katragadda told me) Map Maker users have been responsible for creating whole maps from nothing. Here in the U.S., the editing features will allow the addition of more commercial data (stores and other businesses locations) and highly specific street information that's currently missing, like temporary closures due to construction projects. Google Maps, Google Earth, and Google's mobile products will all use this data. Google's route-planning services will take traffic-related updates into consideration.

Katragadda envisions small-town property or business owners taking an interest in how Google represents their location, adding features like nearby park paths to maps to possibly make their neighborhoods look more attractive.

Map Maker lets Google users update the U.S. basemap.

Anyone can edit, sort of Any logged-in Google user can edit a map, but changes from newbies aren't automatically reflected on live maps that the world can see. Users' updates go through a vetting process that asks previously blessed users to approve or deny edits (or send them back for revision). As users get better at getting edits posted without edits, they get closer to unlocking the capability to update public maps without having to go through an approval process, and to becoming moderators themselves to other users' edits.

The idea, Katragadda says, is to make "living and breathing" Google Maps. Fully approved users will see their updates go live "in minutes," and see traffic direction use the updates shortly after that. So owners of mobile businesses, like the new hotness in dining, food trucks, will want to get approved quickly. However, today's announcement does not have a mobile map editor component' the editor requires a full Web browser.

He adds that an update to the Map Maker tool will also bring in Google Street View images, from which community cartographers can use to construct or edit map data. A new live update viewer will also show what the community is editing at the given moment.

Map Maker lets you trace satellite imagery.

Google won't take input from other community map sources, like Open Street Map or Waze. There are two reasons for this, one of which I got from Google, the other unstated. First, the user approval system was created for this project and isn't even used by other Google services. Adapting it to other user systems is just not on the project plan at the moment. The unstated reason: Google's data licensing is incompatible with other community maps. OpenStreetMap, for example, uses Creative Commons. Google does not: What you put on Google, Google owns.

Google has different levels of control for different regions of the world. Maps can be intensely political, and contested regions won't be open to community edits from just anyone. In addition to opening up maps to annoying Wikipedia-like political edit fights, factions can put either sensitive or misleading data into Google Maps to influence peoples' movement' Google will keep a tighter grip on the data in disputed areas that it will on, say, downtown Boise. Katragadda told me the balance is difficult but important. "Very few products allow canonical data to be edited by the user," he said, and the team's guideline is to both "look for ways to make the Web more democratic," and "reflect reality." That can be a tough line to walk, as any mapmaker will attest.

The third and fourth dimensions Today's announcement is about letting users update the standard Google Maps, but in the future the maps themselves may get new capabilities. One is support for the third dimension. Katragadda notably told me that users will be able to update store locations in "strip malls"--which are flat. Google Maps doesn't yet support stores or businesses layered on top of each other, even though his division also runs the Building Maker tool for Maps. 3D map support will come later, he said.

Google Maps also doesn't support event-based map data, such as no-left-turn restrictions that only apply at certain times of the day. That's another feature that may come to Google Maps (and Traffic) in the future, but the Google people I talked with had no announcement on that.

Finally, there's also the dimension of money. Giving business owners control of what shows up on local maps is a key way to improve both maps' utility for consumers and interest in local advertising. That's a big driver for online mapping and perfectly aligned with Google's main business of selling user- and content-aware ad placements.