Google will announce today that its mobile maps will provide live traffic data on 130 new U.S. cities, from Kalamazoo, Michigan, to Tuscaloosa, Alabama, as well as in the capitals of Colombia, Costa Rica, and Panama. The live traffic coverage in China and many European countries will also be increased. Google now offers traffic data in more than 50 countries, most of them added in the last year.

Google took a roundabout route to building the world’s largest traffic-jam surveillance network—by providing the operating system for some 400 million smartphones. Few people realize it, but using the mapping function on an Android-powered device sends Google anonymous data on your position and current speed that it uses to figure out traffic flows—if you’re traveling along a freeway at 60 miles per hour, but suddenly slow to a crawl, Google knows that traffic most likely just snarled up. Google new announcement underscores the power of that mobile crowdsourcing approach.

“What really enables that rapid scaling is anonymous crowdsourced data from Android users,” says Stephan Seyboth, Google’s product manager for traffic, transit, and directions features of Google Maps.

Traditionally, local authorities have gathered data on traffic flows using detectors embedded into the road surface. “They’re expensive to install, so they only cover limited stretches of road,” says Seyboth. “Our anonymous crowdsourced phone data allows us to reach countries that are out of reach to that traditional kind of traffic service.”

Seyboth says Google decided to launch its live traffic service in the new cities based on measures of the quality and quantity of data on traffic flows there. “It’s a function of Android use and adoption,” he says, though he declines to say how many Android users a city needs to get a good picture of traffic flows.

The information sent to the company specifies only a location and speed, not any information that can be tied to a user or particular device, says Seyboth. The start and end points of a route are not uploaded. “You can’t identify individual users or phones by looking at their track.”

Google’s mapping apps currently choose a route for users based on its knowledge of traffic conditions when they start their journey. Some other companies are beginning to explore whether a driving direction service could attempt to orchestrate all its users to avoid the creation of jams anywhere (see “An App that Could Stop Traffic”).

“That is a situation that some groups in [Google] research are looking into,” says Seyboth. “Doing a crowd-aware rerouting is probably the next step.”

Google’s expansion of the live traffic information available via its maps raises the bar for Apple, which announced in June that it had built its own mobile maps service that will replace Google’s as the default on the iPhone and iPad this fall (see “Apple Charts a New Course for Mobile Maps”). That service will also use anonymous, crowdsourced traffic data from its users to track traffic flows and shape route guidance.

Due to much lower uptake of iPhones in poorer countries, Apple will likely be unable to offer traffic data in some places that Google can, such as Colombia and China, where Android phones are much more common. In the U.S. and other rich nations, though, the playing field is more level, although Android phones are still more numerous. Google says that a total of 400 million Android devices have been activated since its operating system became available, almost all of them phones. Apple reported earlier this year that over 244 million iPhones have been sold since the first model of the device launched in 2007.

Apple’s announcement that it would provide its own maps came in the wake of it buying up several mapping technology companies, such as C3, which creates detailed, accurate 3-D maps from aerial photos (see “Ultrasharp 3-D Maps”). The decision to demote Google’s maps is seen by some as an attempt from Apple to tighten control over its mobile computing experience, and a move that also opens up potential mobile advertizing revenue.